xref: /btstack/src/hci.c (revision eb8d95caa2401cdef2e12b7d99c8137c1d16f172)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hci.c"
39 
40 /*
41  *  hci.c
42  *
43  *  Created by Matthias Ringwald on 4/29/09.
44  *
45  */
46 
47 #include "btstack_config.h"
48 
49 
50 #ifdef ENABLE_CLASSIC
51 #ifdef HAVE_EMBEDDED_TICK
52 #include "btstack_run_loop_embedded.h"
53 #endif
54 #endif
55 
56 #ifdef ENABLE_BLE
57 #include "gap.h"
58 #include "ble/le_device_db.h"
59 #endif
60 
61 #include <stdarg.h>
62 #include <string.h>
63 #include <inttypes.h>
64 
65 #include "btstack_debug.h"
66 #include "btstack_event.h"
67 #include "btstack_linked_list.h"
68 #include "btstack_memory.h"
69 #include "bluetooth_company_id.h"
70 #include "bluetooth_data_types.h"
71 #include "gap.h"
72 #include "hci.h"
73 #include "hci_cmd.h"
74 #include "hci_dump.h"
75 #include "ad_parser.h"
76 
77 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
78 #ifndef HCI_HOST_ACL_PACKET_NUM
79 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_NUM"
80 #endif
81 #ifndef HCI_HOST_ACL_PACKET_LEN
82 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_ACL_PACKET_LEN"
83 #endif
84 #ifndef HCI_HOST_SCO_PACKET_NUM
85 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_NUM"
86 #endif
87 #ifndef HCI_HOST_SCO_PACKET_LEN
88 #error "ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL requires to define HCI_HOST_SCO_PACKET_LEN"
89 #endif
90 #endif
91 
92 #if defined(ENABLE_SCO_OVER_HCI) && defined(ENABLE_SCO_OVER_PCM)
93 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM."
94 #endif
95 
96 #if defined(ENABLE_SCO_OVER_HCI) && defined(HAVE_SCO_TRANSPORT)
97 #error "SCO data can either be routed over HCI or over PCM, but not over both. Please only enable ENABLE_SCO_OVER_HCI or HAVE_SCO_TRANSPORT."
98 #endif
99 
100 #define HCI_CONNECTION_TIMEOUT_MS 10000
101 
102 #ifndef HCI_RESET_RESEND_TIMEOUT_MS
103 #define HCI_RESET_RESEND_TIMEOUT_MS 200
104 #endif
105 
106 // Names are arbitrarily shortened to 32 bytes if not requested otherwise
107 #ifndef GAP_INQUIRY_MAX_NAME_LEN
108 #define GAP_INQUIRY_MAX_NAME_LEN 32
109 #endif
110 
111 // GAP inquiry state: 0 = off, 0x01 - 0x30 = requested duration, 0xfe = active, 0xff = stop requested
112 #define GAP_INQUIRY_DURATION_MIN       0x01
113 #define GAP_INQUIRY_DURATION_MAX       0x30
114 #define GAP_INQUIRY_STATE_IDLE         0x00
115 #define GAP_INQUIRY_STATE_W4_ACTIVE    0x80
116 #define GAP_INQUIRY_STATE_ACTIVE       0x81
117 #define GAP_INQUIRY_STATE_W2_CANCEL    0x82
118 #define GAP_INQUIRY_STATE_W4_CANCELLED 0x83
119 
120 // GAP Remote Name Request
121 #define GAP_REMOTE_NAME_STATE_IDLE 0
122 #define GAP_REMOTE_NAME_STATE_W2_SEND 1
123 #define GAP_REMOTE_NAME_STATE_W4_COMPLETE 2
124 
125 // GAP Pairing
126 #define GAP_PAIRING_STATE_IDLE                       0
127 #define GAP_PAIRING_STATE_SEND_PIN                   1
128 #define GAP_PAIRING_STATE_SEND_PIN_NEGATIVE          2
129 #define GAP_PAIRING_STATE_SEND_PASSKEY               3
130 #define GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE      4
131 #define GAP_PAIRING_STATE_SEND_CONFIRMATION          5
132 #define GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE 6
133 #define GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE  7
134 
135 // prototypes
136 #ifdef ENABLE_CLASSIC
137 static void hci_update_scan_enable(void);
138 static void hci_emit_discoverable_enabled(uint8_t enabled);
139 static int  hci_local_ssp_activated(void);
140 static bool hci_remote_ssp_supported(hci_con_handle_t con_handle);
141 static bool hci_ssp_supported(hci_connection_t * connection);
142 static void hci_notify_if_sco_can_send_now(void);
143 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status);
144 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection);
145 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level);
146 static void hci_connection_timeout_handler(btstack_timer_source_t *timer);
147 static void hci_connection_timestamp(hci_connection_t *connection);
148 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn);
149 static void gap_inquiry_explode(uint8_t *packet, uint16_t size);
150 #endif
151 
152 static int  hci_power_control_on(void);
153 static void hci_power_control_off(void);
154 static void hci_state_reset(void);
155 static void hci_emit_transport_packet_sent(void);
156 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason);
157 static void hci_emit_nr_connections_changed(void);
158 static void hci_emit_hci_open_failed(void);
159 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status);
160 static void hci_emit_event(uint8_t * event, uint16_t size, int dump);
161 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size);
162 static void hci_run(void);
163 static int  hci_is_le_connection(hci_connection_t * connection);
164 static int  hci_number_free_acl_slots_for_connection_type( bd_addr_type_t address_type);
165 
166 #ifdef ENABLE_CLASSIC
167 static int hci_have_usb_transport(void);
168 #endif
169 
170 #ifdef ENABLE_BLE
171 #ifdef ENABLE_LE_CENTRAL
172 // called from test/ble_client/advertising_data_parser.c
173 void le_handle_advertisement_report(uint8_t *packet, uint16_t size);
174 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address);
175 static hci_connection_t * gap_get_outgoing_connection(void);
176 #endif
177 #endif
178 
179 // the STACK is here
180 #ifndef HAVE_MALLOC
181 static hci_stack_t   hci_stack_static;
182 #endif
183 static hci_stack_t * hci_stack = NULL;
184 
185 #ifdef ENABLE_CLASSIC
186 // default name
187 static const char * default_classic_name = "BTstack 00:00:00:00:00:00";
188 
189 // test helper
190 static uint8_t disable_l2cap_timeouts = 0;
191 #endif
192 
193 // reset connection state on create and on reconnect
194 // don't overwrite addr, con handle, role
195 static void hci_connection_init(hci_connection_t * conn){
196     conn->authentication_flags = AUTH_FLAG_NONE;
197     conn->bonding_flags = 0;
198     conn->requested_security_level = LEVEL_0;
199 #ifdef ENABLE_CLASSIC
200     conn->request_role = HCI_ROLE_INVALID;
201     conn->sniff_subrating_max_latency = 0xffff;
202     conn->qos_service_type = HCI_SERVICE_TYPE_INVALID;
203     conn->link_key_type = INVALID_LINK_KEY;
204     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
205     btstack_run_loop_set_timer_context(&conn->timeout, conn);
206     hci_connection_timestamp(conn);
207 #endif
208     conn->acl_recombination_length = 0;
209     conn->acl_recombination_pos = 0;
210     conn->num_packets_sent = 0;
211 
212     conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
213 #ifdef ENABLE_BLE
214     conn->le_phy_update_all_phys = 0xff;
215 #endif
216 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
217     conn->le_max_tx_octets = 27;
218 #endif
219 #ifdef ENABLE_CLASSIC_PAIRING_OOB
220     conn->classic_oob_c_192 = NULL;
221     conn->classic_oob_r_192 = NULL;
222     conn->classic_oob_c_256 = NULL;
223     conn->classic_oob_r_256 = NULL;
224 #endif
225 }
226 
227 /**
228  * create connection for given address
229  *
230  * @return connection OR NULL, if no memory left
231  */
232 static hci_connection_t * create_connection_for_bd_addr_and_type(const bd_addr_t addr, bd_addr_type_t addr_type){
233     log_info("create_connection_for_addr %s, type %x", bd_addr_to_str(addr), addr_type);
234 
235     hci_connection_t * conn = btstack_memory_hci_connection_get();
236     if (!conn) return NULL;
237     hci_connection_init(conn);
238 
239     bd_addr_copy(conn->address, addr);
240     conn->address_type = addr_type;
241     conn->con_handle = HCI_CON_HANDLE_INVALID;
242     conn->role = HCI_ROLE_INVALID;
243 
244     btstack_linked_list_add(&hci_stack->connections, (btstack_linked_item_t *) conn);
245 
246     return conn;
247 }
248 
249 
250 /**
251  * get le connection parameter range
252 *
253  * @return le connection parameter range struct
254  */
255 void gap_get_connection_parameter_range(le_connection_parameter_range_t * range){
256     *range = hci_stack->le_connection_parameter_range;
257 }
258 
259 /**
260  * set le connection parameter range
261  *
262  */
263 
264 void gap_set_connection_parameter_range(le_connection_parameter_range_t *range){
265     hci_stack->le_connection_parameter_range = *range;
266 }
267 
268 /**
269  * @brief Test if connection parameters are inside in existing rage
270  * @param conn_interval_min (unit: 1.25ms)
271  * @param conn_interval_max (unit: 1.25ms)
272  * @param conn_latency
273  * @param supervision_timeout (unit: 10ms)
274  * @returns 1 if included
275  */
276 int gap_connection_parameter_range_included(le_connection_parameter_range_t * existing_range, uint16_t le_conn_interval_min, uint16_t le_conn_interval_max, uint16_t le_conn_latency, uint16_t le_supervision_timeout){
277     if (le_conn_interval_min < existing_range->le_conn_interval_min) return 0;
278     if (le_conn_interval_max > existing_range->le_conn_interval_max) return 0;
279 
280     if (le_conn_latency < existing_range->le_conn_latency_min) return 0;
281     if (le_conn_latency > existing_range->le_conn_latency_max) return 0;
282 
283     if (le_supervision_timeout < existing_range->le_supervision_timeout_min) return 0;
284     if (le_supervision_timeout > existing_range->le_supervision_timeout_max) return 0;
285 
286     return 1;
287 }
288 
289 /**
290  * @brief Set max number of connections in LE Peripheral role (if Bluetooth Controller supports it)
291  * @note: default: 1
292  * @param max_peripheral_connections
293  */
294 #ifdef ENABLE_LE_PERIPHERAL
295 void gap_set_max_number_peripheral_connections(int max_peripheral_connections){
296     hci_stack->le_max_number_peripheral_connections = max_peripheral_connections;
297 }
298 #endif
299 
300 /**
301  * get hci connections iterator
302  *
303  * @return hci connections iterator
304  */
305 
306 void hci_connections_get_iterator(btstack_linked_list_iterator_t *it){
307     btstack_linked_list_iterator_init(it, &hci_stack->connections);
308 }
309 
310 /**
311  * get connection for a given handle
312  *
313  * @return connection OR NULL, if not found
314  */
315 hci_connection_t * hci_connection_for_handle(hci_con_handle_t con_handle){
316     btstack_linked_list_iterator_t it;
317     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
318     while (btstack_linked_list_iterator_has_next(&it)){
319         hci_connection_t * item = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
320         if ( item->con_handle == con_handle ) {
321             return item;
322         }
323     }
324     return NULL;
325 }
326 
327 /**
328  * get connection for given address
329  *
330  * @return connection OR NULL, if not found
331  */
332 hci_connection_t * hci_connection_for_bd_addr_and_type(const bd_addr_t  addr, bd_addr_type_t addr_type){
333     btstack_linked_list_iterator_t it;
334     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
335     while (btstack_linked_list_iterator_has_next(&it)){
336         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
337         if (connection->address_type != addr_type)  continue;
338         if (memcmp(addr, connection->address, 6) != 0) continue;
339         return connection;
340     }
341     return NULL;
342 }
343 
344 inline static void connectionClearAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
345     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags & ~flags);
346 }
347 
348 inline static void connectionSetAuthenticationFlags(hci_connection_t * conn, hci_authentication_flags_t flags){
349     conn->authentication_flags = (hci_authentication_flags_t)(conn->authentication_flags | flags);
350 }
351 
352 #ifdef ENABLE_CLASSIC
353 
354 #ifdef ENABLE_SCO_OVER_HCI
355 static int hci_number_sco_connections(void){
356     int connections = 0;
357     btstack_linked_list_iterator_t it;
358     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
359     while (btstack_linked_list_iterator_has_next(&it)){
360         hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it);
361         if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
362         connections++;
363     }
364     return connections;
365 }
366 #endif
367 
368 static void hci_connection_timeout_handler(btstack_timer_source_t *timer){
369     hci_connection_t * connection = (hci_connection_t *) btstack_run_loop_get_timer_context(timer);
370 #ifdef HAVE_EMBEDDED_TICK
371     if (btstack_run_loop_embedded_get_ticks() > connection->timestamp + btstack_run_loop_embedded_ticks_for_ms(HCI_CONNECTION_TIMEOUT_MS)){
372         // connections might be timed out
373         hci_emit_l2cap_check_timeout(connection);
374     }
375 #else
376     if (btstack_run_loop_get_time_ms() > (connection->timestamp + HCI_CONNECTION_TIMEOUT_MS)){
377         // connections might be timed out
378         hci_emit_l2cap_check_timeout(connection);
379     }
380 #endif
381 }
382 
383 static void hci_connection_timestamp(hci_connection_t *connection){
384 #ifdef HAVE_EMBEDDED_TICK
385     connection->timestamp = btstack_run_loop_embedded_get_ticks();
386 #else
387     connection->timestamp = btstack_run_loop_get_time_ms();
388 #endif
389 }
390 
391 /**
392  * add authentication flags and reset timer
393  * @note: assumes classic connection
394  * @note: bd_addr is passed in as litle endian uint8_t * as it is called from parsing packets
395  */
396 static void hci_add_connection_flags_for_flipped_bd_addr(uint8_t *bd_addr, hci_authentication_flags_t flags){
397     bd_addr_t addr;
398     reverse_bd_addr(bd_addr, addr);
399     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
400     if (conn) {
401         connectionSetAuthenticationFlags(conn, flags);
402         hci_connection_timestamp(conn);
403     }
404 }
405 
406 static bool hci_pairing_active(hci_connection_t * hci_connection){
407     return (hci_connection->authentication_flags & AUTH_FLAG_PAIRING_ACTIVE_MASK) != 0;
408 }
409 
410 static void hci_pairing_started(hci_connection_t * hci_connection, bool ssp){
411     if (hci_pairing_active(hci_connection)) return;
412     if (ssp){
413         hci_connection->authentication_flags |= AUTH_FLAG_SSP_PAIRING_ACTIVE;
414     } else {
415         hci_connection->authentication_flags |= AUTH_FLAG_LEGACY_PAIRING_ACTIVE;
416     }
417     // if we are initiator, we have sent an HCI Authenticate Request
418     bool initiator = (hci_connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0;
419 
420     // if we are responder, use minimal service security level as required level
421     if (!initiator){
422         hci_connection->requested_security_level = (gap_security_level_t) btstack_max((uint32_t) hci_connection->requested_security_level, (uint32_t) hci_stack->gap_minimal_service_security_level);
423     }
424 
425     log_info("pairing started, ssp %u, initiator %u, requested level %u", (int) ssp, (int) initiator, hci_connection->requested_security_level);
426 
427     uint8_t event[12];
428     event[0] = GAP_EVENT_PAIRING_STARTED;
429     event[1] = 10;
430     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
431     reverse_bd_addr(hci_connection->address, &event[4]);
432     event[10] = (uint8_t) ssp;
433     event[11] = (uint8_t) initiator;
434     hci_emit_event(event, sizeof(event), 1);
435 }
436 
437 static void hci_pairing_complete(hci_connection_t * hci_connection, uint8_t status){
438     hci_connection->requested_security_level = LEVEL_0;
439     if (!hci_pairing_active(hci_connection)) return;
440     hci_connection->authentication_flags &= ~AUTH_FLAG_PAIRING_ACTIVE_MASK;
441 #ifdef ENABLE_CLASSIC_PAIRING_OOB
442     hci_connection->classic_oob_c_192 = NULL;
443     hci_connection->classic_oob_r_192 = NULL;
444     hci_connection->classic_oob_c_256 = NULL;
445     hci_connection->classic_oob_r_256 = NULL;
446 #endif
447     log_info("pairing complete, status %02x", status);
448 
449     uint8_t event[12];
450     event[0] = GAP_EVENT_PAIRING_COMPLETE;
451     event[1] = 9;
452     little_endian_store_16(event, 2, (uint16_t) hci_connection->con_handle);
453     reverse_bd_addr(hci_connection->address, &event[4]);
454     event[10] = status;
455     hci_emit_event(event, sizeof(event), 1);
456 }
457 
458 bool hci_authentication_active_for_handle(hci_con_handle_t handle){
459     hci_connection_t * conn = hci_connection_for_handle(handle);
460     if (!conn) return false;
461     return hci_pairing_active(conn);
462 }
463 
464 void gap_drop_link_key_for_bd_addr(bd_addr_t addr){
465     if (!hci_stack->link_key_db) return;
466     log_info("gap_drop_link_key_for_bd_addr: %s", bd_addr_to_str(addr));
467     hci_stack->link_key_db->delete_link_key(addr);
468 }
469 
470 void gap_store_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t type){
471     if (!hci_stack->link_key_db) return;
472     log_info("gap_store_link_key_for_bd_addr: %s, type %u", bd_addr_to_str(addr), type);
473     hci_stack->link_key_db->put_link_key(addr, link_key, type);
474 }
475 
476 bool gap_get_link_key_for_bd_addr(bd_addr_t addr, link_key_t link_key, link_key_type_t * type){
477 	if (!hci_stack->link_key_db) return false;
478 	int result = hci_stack->link_key_db->get_link_key(addr, link_key, type) != 0;
479 	log_info("link key for %s available %u, type %u", bd_addr_to_str(addr), result, (int) *type);
480 	return result;
481 }
482 
483 void gap_delete_all_link_keys(void){
484     bd_addr_t  addr;
485     link_key_t link_key;
486     link_key_type_t type;
487     btstack_link_key_iterator_t it;
488     int ok = gap_link_key_iterator_init(&it);
489     if (!ok) {
490         log_error("could not initialize iterator");
491         return;
492     }
493     while (gap_link_key_iterator_get_next(&it, addr, link_key, &type)){
494         gap_drop_link_key_for_bd_addr(addr);
495     }
496     gap_link_key_iterator_done(&it);
497 }
498 
499 int gap_link_key_iterator_init(btstack_link_key_iterator_t * it){
500     if (!hci_stack->link_key_db) return 0;
501     if (!hci_stack->link_key_db->iterator_init) return 0;
502     return hci_stack->link_key_db->iterator_init(it);
503 }
504 int gap_link_key_iterator_get_next(btstack_link_key_iterator_t * it, bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * type){
505     if (!hci_stack->link_key_db) return 0;
506     return hci_stack->link_key_db->iterator_get_next(it, bd_addr, link_key, type);
507 }
508 void gap_link_key_iterator_done(btstack_link_key_iterator_t * it){
509     if (!hci_stack->link_key_db) return;
510     hci_stack->link_key_db->iterator_done(it);
511 }
512 #endif
513 
514 static bool hci_is_le_connection_type(bd_addr_type_t address_type){
515     switch (address_type){
516         case BD_ADDR_TYPE_LE_PUBLIC:
517         case BD_ADDR_TYPE_LE_RANDOM:
518         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_PUBLIC:
519         case BD_ADDR_TYPE_LE_PRIVAT_FALLBACK_RANDOM:
520             return true;
521         default:
522             return false;
523     }
524 }
525 
526 static int hci_is_le_connection(hci_connection_t * connection){
527     return hci_is_le_connection_type(connection->address_type);
528 }
529 
530 /**
531  * count connections
532  */
533 static int nr_hci_connections(void){
534     int count = 0;
535     btstack_linked_item_t *it;
536     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL ; it = it->next){
537         count++;
538     }
539     return count;
540 }
541 
542 static int hci_number_free_acl_slots_for_connection_type(bd_addr_type_t address_type){
543 
544     unsigned int num_packets_sent_classic = 0;
545     unsigned int num_packets_sent_le = 0;
546 
547     btstack_linked_item_t *it;
548     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
549         hci_connection_t * connection = (hci_connection_t *) it;
550         if (hci_is_le_connection(connection)){
551             num_packets_sent_le += connection->num_packets_sent;
552         }
553         if (connection->address_type == BD_ADDR_TYPE_ACL){
554             num_packets_sent_classic += connection->num_packets_sent;
555         }
556     }
557     log_debug("ACL classic buffers: %u used of %u", num_packets_sent_classic, hci_stack->acl_packets_total_num);
558     int free_slots_classic = hci_stack->acl_packets_total_num - num_packets_sent_classic;
559     int free_slots_le = 0;
560 
561     if (free_slots_classic < 0){
562         log_error("hci_number_free_acl_slots: outgoing classic packets (%u) > total classic packets (%u)", num_packets_sent_classic, hci_stack->acl_packets_total_num);
563         return 0;
564     }
565 
566     if (hci_stack->le_acl_packets_total_num){
567         // if we have LE slots, they are used
568         free_slots_le = hci_stack->le_acl_packets_total_num - num_packets_sent_le;
569         if (free_slots_le < 0){
570             log_error("hci_number_free_acl_slots: outgoing le packets (%u) > total le packets (%u)", num_packets_sent_le, hci_stack->le_acl_packets_total_num);
571             return 0;
572         }
573     } else {
574         // otherwise, classic slots are used for LE, too
575         free_slots_classic -= num_packets_sent_le;
576         if (free_slots_classic < 0){
577             log_error("hci_number_free_acl_slots: outgoing classic + le packets (%u + %u) > total packets (%u)", num_packets_sent_classic, num_packets_sent_le, hci_stack->acl_packets_total_num);
578             return 0;
579         }
580     }
581 
582     switch (address_type){
583         case BD_ADDR_TYPE_UNKNOWN:
584             log_error("hci_number_free_acl_slots: unknown address type");
585             return 0;
586 
587         case BD_ADDR_TYPE_ACL:
588             return free_slots_classic;
589 
590         default:
591            if (hci_stack->le_acl_packets_total_num){
592                return free_slots_le;
593            }
594            return free_slots_classic;
595     }
596 }
597 
598 int hci_number_free_acl_slots_for_handle(hci_con_handle_t con_handle){
599     // get connection type
600     hci_connection_t * connection = hci_connection_for_handle(con_handle);
601     if (!connection){
602         log_error("hci_number_free_acl_slots: handle 0x%04x not in connection list", con_handle);
603         return 0;
604     }
605     return hci_number_free_acl_slots_for_connection_type(connection->address_type);
606 }
607 
608 #ifdef ENABLE_CLASSIC
609 static int hci_number_free_sco_slots(void){
610     unsigned int num_sco_packets_sent  = 0;
611     btstack_linked_item_t *it;
612     if (hci_stack->synchronous_flow_control_enabled){
613         // explicit flow control
614         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
615             hci_connection_t * connection = (hci_connection_t *) it;
616             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
617             num_sco_packets_sent += connection->num_packets_sent;
618         }
619         if (num_sco_packets_sent > hci_stack->sco_packets_total_num){
620             log_info("hci_number_free_sco_slots:packets (%u) > total packets (%u)", num_sco_packets_sent, hci_stack->sco_packets_total_num);
621             return 0;
622         }
623         return hci_stack->sco_packets_total_num - num_sco_packets_sent;
624     } else {
625         // implicit flow control -- TODO
626         int num_ready = 0;
627         for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
628             hci_connection_t * connection = (hci_connection_t *) it;
629             if (connection->address_type != BD_ADDR_TYPE_SCO) continue;
630             if (connection->sco_tx_ready == 0) continue;
631             num_ready++;
632         }
633         return num_ready;
634     }
635 }
636 #endif
637 
638 // only used to send HCI Host Number Completed Packets
639 static int hci_can_send_comand_packet_transport(void){
640     if (hci_stack->hci_packet_buffer_reserved) return 0;
641 
642     // check for async hci transport implementations
643     if (hci_stack->hci_transport->can_send_packet_now){
644         if (!hci_stack->hci_transport->can_send_packet_now(HCI_COMMAND_DATA_PACKET)){
645             return 0;
646         }
647     }
648     return 1;
649 }
650 
651 // new functions replacing hci_can_send_packet_now[_using_packet_buffer]
652 bool hci_can_send_command_packet_now(void){
653     if (hci_can_send_comand_packet_transport() == 0) return false;
654     return hci_stack->num_cmd_packets > 0u;
655 }
656 
657 static int hci_transport_can_send_prepared_packet_now(uint8_t packet_type){
658     // check for async hci transport implementations
659     if (!hci_stack->hci_transport->can_send_packet_now) return true;
660     return hci_stack->hci_transport->can_send_packet_now(packet_type);
661 }
662 
663 static bool hci_can_send_prepared_acl_packet_for_address_type(bd_addr_type_t address_type){
664     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
665     return hci_number_free_acl_slots_for_connection_type(address_type) > 0;
666 }
667 
668 bool hci_can_send_acl_le_packet_now(void){
669     if (hci_stack->hci_packet_buffer_reserved) return false;
670     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_LE_PUBLIC);
671 }
672 
673 bool hci_can_send_prepared_acl_packet_now(hci_con_handle_t con_handle) {
674     if (!hci_transport_can_send_prepared_packet_now(HCI_ACL_DATA_PACKET)) return false;
675     return hci_number_free_acl_slots_for_handle(con_handle) > 0;
676 }
677 
678 bool hci_can_send_acl_packet_now(hci_con_handle_t con_handle){
679     if (hci_stack->hci_packet_buffer_reserved) return false;
680     return hci_can_send_prepared_acl_packet_now(con_handle);
681 }
682 
683 #ifdef ENABLE_CLASSIC
684 bool hci_can_send_acl_classic_packet_now(void){
685     if (hci_stack->hci_packet_buffer_reserved) return false;
686     return hci_can_send_prepared_acl_packet_for_address_type(BD_ADDR_TYPE_ACL);
687 }
688 
689 bool hci_can_send_prepared_sco_packet_now(void){
690     if (!hci_transport_can_send_prepared_packet_now(HCI_SCO_DATA_PACKET)) return false;
691     if (hci_have_usb_transport()){
692         return hci_stack->sco_can_send_now;
693     } else {
694         return hci_number_free_sco_slots() > 0;
695     }
696 }
697 
698 bool hci_can_send_sco_packet_now(void){
699     if (hci_stack->hci_packet_buffer_reserved) return false;
700     return hci_can_send_prepared_sco_packet_now();
701 }
702 
703 void hci_request_sco_can_send_now_event(void){
704     hci_stack->sco_waiting_for_can_send_now = 1;
705     hci_notify_if_sco_can_send_now();
706 }
707 #endif
708 
709 // used for internal checks in l2cap.c
710 bool hci_is_packet_buffer_reserved(void){
711     return hci_stack->hci_packet_buffer_reserved;
712 }
713 
714 // reserves outgoing packet buffer. @returns 1 if successful
715 bool hci_reserve_packet_buffer(void){
716     if (hci_stack->hci_packet_buffer_reserved) {
717         log_error("hci_reserve_packet_buffer called but buffer already reserved");
718         return false;
719     }
720     hci_stack->hci_packet_buffer_reserved = true;
721     return true;
722 }
723 
724 void hci_release_packet_buffer(void){
725     hci_stack->hci_packet_buffer_reserved = false;
726 }
727 
728 // assumption: synchronous implementations don't provide can_send_packet_now as they don't keep the buffer after the call
729 static int hci_transport_synchronous(void){
730     return hci_stack->hci_transport->can_send_packet_now == NULL;
731 }
732 
733 static uint8_t hci_send_acl_packet_fragments(hci_connection_t *connection){
734 
735     // log_info("hci_send_acl_packet_fragments  %u/%u (con 0x%04x)", hci_stack->acl_fragmentation_pos, hci_stack->acl_fragmentation_total_size, connection->con_handle);
736 
737     // max ACL data packet length depends on connection type (LE vs. Classic) and available buffers
738     uint16_t max_acl_data_packet_length = hci_stack->acl_data_packet_length;
739     if (hci_is_le_connection(connection) && (hci_stack->le_data_packets_length > 0u)){
740         max_acl_data_packet_length = hci_stack->le_data_packets_length;
741     }
742 
743 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
744     if (hci_is_le_connection(connection) && (connection->le_max_tx_octets < max_acl_data_packet_length)){
745         max_acl_data_packet_length = connection->le_max_tx_octets;
746     }
747 #endif
748 
749     log_debug("hci_send_acl_packet_fragments entered");
750 
751     uint8_t status = ERROR_CODE_SUCCESS;
752     // multiple packets could be send on a synchronous HCI transport
753     while (true){
754 
755         log_debug("hci_send_acl_packet_fragments loop entered");
756 
757         // get current data
758         const uint16_t acl_header_pos = hci_stack->acl_fragmentation_pos - 4u;
759         int current_acl_data_packet_length = hci_stack->acl_fragmentation_total_size - hci_stack->acl_fragmentation_pos;
760         bool more_fragments = false;
761 
762         // if ACL packet is larger than Bluetooth packet buffer, only send max_acl_data_packet_length
763         if (current_acl_data_packet_length > max_acl_data_packet_length){
764             more_fragments = true;
765             current_acl_data_packet_length = max_acl_data_packet_length;
766         }
767 
768         // copy handle_and_flags if not first fragment and update packet boundary flags to be 01 (continuing fragmnent)
769         if (acl_header_pos > 0u){
770             uint16_t handle_and_flags = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
771             handle_and_flags = (handle_and_flags & 0xcfffu) | (1u << 12u);
772             little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos, handle_and_flags);
773         }
774 
775         // update header len
776         little_endian_store_16(hci_stack->hci_packet_buffer, acl_header_pos + 2u, current_acl_data_packet_length);
777 
778         // count packet
779         connection->num_packets_sent++;
780         log_debug("hci_send_acl_packet_fragments loop before send (more fragments %d)", (int) more_fragments);
781 
782         // update state for next fragment (if any) as "transport done" might be sent during send_packet already
783         if (more_fragments){
784             // update start of next fragment to send
785             hci_stack->acl_fragmentation_pos += current_acl_data_packet_length;
786         } else {
787             // done
788             hci_stack->acl_fragmentation_pos = 0;
789             hci_stack->acl_fragmentation_total_size = 0;
790         }
791 
792         // send packet
793         uint8_t * packet = &hci_stack->hci_packet_buffer[acl_header_pos];
794         const int size = current_acl_data_packet_length + 4;
795         hci_dump_packet(HCI_ACL_DATA_PACKET, 0, packet, size);
796         hci_stack->acl_fragmentation_tx_active = 1;
797         int err = hci_stack->hci_transport->send_packet(HCI_ACL_DATA_PACKET, packet, size);
798         if (err != 0){
799             // no error from HCI Transport expected
800             status = ERROR_CODE_HARDWARE_FAILURE;
801         }
802 
803         log_debug("hci_send_acl_packet_fragments loop after send (more fragments %d)", (int) more_fragments);
804 
805         // done yet?
806         if (!more_fragments) break;
807 
808         // can send more?
809         if (!hci_can_send_prepared_acl_packet_now(connection->con_handle)) return status;
810     }
811 
812     log_debug("hci_send_acl_packet_fragments loop over");
813 
814     // release buffer now for synchronous transport
815     if (hci_transport_synchronous()){
816         hci_stack->acl_fragmentation_tx_active = 0;
817         hci_release_packet_buffer();
818         hci_emit_transport_packet_sent();
819     }
820 
821     return status;
822 }
823 
824 // pre: caller has reserved the packet buffer
825 uint8_t hci_send_acl_packet_buffer(int size){
826     btstack_assert(hci_stack->hci_packet_buffer_reserved);
827 
828     uint8_t * packet = hci_stack->hci_packet_buffer;
829     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
830 
831     // check for free places on Bluetooth module
832     if (!hci_can_send_prepared_acl_packet_now(con_handle)) {
833         log_error("hci_send_acl_packet_buffer called but no free ACL buffers on controller");
834         hci_release_packet_buffer();
835         hci_emit_transport_packet_sent();
836         return BTSTACK_ACL_BUFFERS_FULL;
837     }
838 
839     hci_connection_t *connection = hci_connection_for_handle( con_handle);
840     if (!connection) {
841         log_error("hci_send_acl_packet_buffer called but no connection for handle 0x%04x", con_handle);
842         hci_release_packet_buffer();
843         hci_emit_transport_packet_sent();
844         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
845     }
846 
847 #ifdef ENABLE_CLASSIC
848     hci_connection_timestamp(connection);
849 #endif
850 
851     // hci_dump_packet( HCI_ACL_DATA_PACKET, 0, packet, size);
852 
853     // setup data
854     hci_stack->acl_fragmentation_total_size = size;
855     hci_stack->acl_fragmentation_pos = 4;   // start of L2CAP packet
856 
857     return hci_send_acl_packet_fragments(connection);
858 }
859 
860 #ifdef ENABLE_CLASSIC
861 // pre: caller has reserved the packet buffer
862 uint8_t hci_send_sco_packet_buffer(int size){
863     btstack_assert(hci_stack->hci_packet_buffer_reserved);
864 
865     uint8_t * packet = hci_stack->hci_packet_buffer;
866 
867     // skip checks in loopback mode
868     if (!hci_stack->loopback_mode){
869         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);   // same for ACL and SCO
870 
871         // check for free places on Bluetooth module
872         if (!hci_can_send_prepared_sco_packet_now()) {
873             log_error("hci_send_sco_packet_buffer called but no free SCO buffers on controller");
874             hci_release_packet_buffer();
875             hci_emit_transport_packet_sent();
876             return BTSTACK_ACL_BUFFERS_FULL;
877         }
878 
879         // track send packet in connection struct
880         hci_connection_t *connection = hci_connection_for_handle( con_handle);
881         if (!connection) {
882             log_error("hci_send_sco_packet_buffer called but no connection for handle 0x%04x", con_handle);
883             hci_release_packet_buffer();
884             hci_emit_transport_packet_sent();
885             return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
886         }
887 
888         if (hci_have_usb_transport()){
889             // token used
890             hci_stack->sco_can_send_now = false;
891         } else {
892             if (hci_stack->synchronous_flow_control_enabled){
893                 connection->num_packets_sent++;
894             } else {
895                 connection->sco_tx_ready--;
896             }
897         }
898     }
899 
900     hci_dump_packet( HCI_SCO_DATA_PACKET, 0, packet, size);
901 
902 #ifdef HAVE_SCO_TRANSPORT
903     hci_stack->sco_transport->send_packet(packet, size);
904     hci_release_packet_buffer();
905     hci_emit_transport_packet_sent();
906 
907     return 0;
908 #else
909     int err = hci_stack->hci_transport->send_packet(HCI_SCO_DATA_PACKET, packet, size);
910     if (hci_transport_synchronous()){
911         hci_release_packet_buffer();
912         hci_emit_transport_packet_sent();
913     }
914 
915     if (err != 0){
916         return ERROR_CODE_HARDWARE_FAILURE;
917     }
918     return ERROR_CODE_SUCCESS;
919 #endif
920 }
921 #endif
922 
923 static void acl_handler(uint8_t *packet, uint16_t size){
924 
925     // get info
926     hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
927     hci_connection_t *conn      = hci_connection_for_handle(con_handle);
928     uint8_t  acl_flags          = READ_ACL_FLAGS(packet);
929     uint16_t acl_length         = READ_ACL_LENGTH(packet);
930 
931     // ignore non-registered handle
932     if (!conn){
933         log_error("acl_handler called with non-registered handle %u!" , con_handle);
934         return;
935     }
936 
937     // assert packet is complete
938     if ((acl_length + 4u) != size){
939         log_error("acl_handler called with ACL packet of wrong size %d, expected %u => dropping packet", size, acl_length + 4);
940         return;
941     }
942 
943 #ifdef ENABLE_CLASSIC
944     // update idle timestamp
945     hci_connection_timestamp(conn);
946 #endif
947 
948 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
949     hci_stack->host_completed_packets = 1;
950     conn->num_packets_completed++;
951 #endif
952 
953     // handle different packet types
954     switch (acl_flags & 0x03u) {
955 
956         case 0x01: // continuation fragment
957 
958             // sanity checks
959             if (conn->acl_recombination_pos == 0u) {
960                 log_error( "ACL Cont Fragment but no first fragment for handle 0x%02x", con_handle);
961                 return;
962             }
963             if ((conn->acl_recombination_pos + acl_length) > (4u + HCI_ACL_BUFFER_SIZE)){
964                 log_error( "ACL Cont Fragment to large: combined packet %u > buffer size %u for handle 0x%02x",
965                     conn->acl_recombination_pos + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
966                 conn->acl_recombination_pos = 0;
967                 return;
968             }
969 
970             // append fragment payload (header already stored)
971             (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + conn->acl_recombination_pos],
972                          &packet[4], acl_length);
973             conn->acl_recombination_pos += acl_length;
974 
975             // forward complete L2CAP packet if complete.
976             if (conn->acl_recombination_pos >= (conn->acl_recombination_length + 4u + 4u)){ // pos already incl. ACL header
977                 hci_emit_acl_packet(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE], conn->acl_recombination_pos);
978                 // reset recombination buffer
979                 conn->acl_recombination_length = 0;
980                 conn->acl_recombination_pos = 0;
981             }
982             break;
983 
984         case 0x02: { // first fragment
985 
986             // sanity check
987             if (conn->acl_recombination_pos) {
988                 log_error( "ACL First Fragment but data in buffer for handle 0x%02x, dropping stale fragments", con_handle);
989                 conn->acl_recombination_pos = 0;
990             }
991 
992             // peek into L2CAP packet!
993             uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
994 
995             // compare fragment size to L2CAP packet size
996             if (acl_length >= (l2cap_length + 4u)){
997                 // forward fragment as L2CAP packet
998                 hci_emit_acl_packet(packet, acl_length + 4u);
999             } else {
1000 
1001                 if (acl_length > HCI_ACL_BUFFER_SIZE){
1002                     log_error( "ACL First Fragment to large: fragment %u > buffer size %u for handle 0x%02x",
1003                         4 + acl_length, 4 + HCI_ACL_BUFFER_SIZE, con_handle);
1004                     return;
1005                 }
1006 
1007                 // store first fragment and tweak acl length for complete package
1008                 (void)memcpy(&conn->acl_recombination_buffer[HCI_INCOMING_PRE_BUFFER_SIZE],
1009                              packet, acl_length + 4u);
1010                 conn->acl_recombination_pos    = acl_length + 4u;
1011                 conn->acl_recombination_length = l2cap_length;
1012                 little_endian_store_16(conn->acl_recombination_buffer, HCI_INCOMING_PRE_BUFFER_SIZE + 2u, l2cap_length +4u);
1013             }
1014             break;
1015 
1016         }
1017         default:
1018             log_error( "acl_handler called with invalid packet boundary flags %u", acl_flags & 0x03);
1019             return;
1020     }
1021 
1022     // execute main loop
1023     hci_run();
1024 }
1025 
1026 static void hci_connection_stop_timer(hci_connection_t * conn){
1027     btstack_run_loop_remove_timer(&conn->timeout);
1028 #ifdef ENABLE_CLASSIC
1029     btstack_run_loop_remove_timer(&conn->timeout_sco);
1030 #endif
1031 }
1032 
1033 static void hci_shutdown_connection(hci_connection_t *conn){
1034     log_info("Connection closed: handle 0x%x, %s", conn->con_handle, bd_addr_to_str(conn->address));
1035 
1036 #ifdef ENABLE_CLASSIC
1037 #if defined(ENABLE_SCO_OVER_HCI) || defined(HAVE_SCO_TRANSPORT)
1038     bd_addr_type_t addr_type = conn->address_type;
1039 #endif
1040 #ifdef HAVE_SCO_TRANSPORT
1041     hci_con_handle_t con_handle = conn->con_handle;
1042 #endif
1043 #endif
1044 
1045     hci_connection_stop_timer(conn);
1046 
1047     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
1048     btstack_memory_hci_connection_free( conn );
1049 
1050     // now it's gone
1051     hci_emit_nr_connections_changed();
1052 
1053 #ifdef ENABLE_CLASSIC
1054 #ifdef ENABLE_SCO_OVER_HCI
1055     // update SCO
1056     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->hci_transport != NULL) && (hci_stack->hci_transport->set_sco_config != NULL)){
1057         hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
1058     }
1059 #endif
1060 #ifdef HAVE_SCO_TRANSPORT
1061     if ((addr_type == BD_ADDR_TYPE_SCO) && (hci_stack->sco_transport != NULL)){
1062         hci_stack->sco_transport->close(con_handle);
1063     }
1064 #endif
1065 #endif
1066 }
1067 
1068 #ifdef ENABLE_CLASSIC
1069 
1070 static const uint16_t packet_type_sizes[] = {
1071     0, HCI_ACL_2DH1_SIZE, HCI_ACL_3DH1_SIZE, HCI_ACL_DM1_SIZE,
1072     HCI_ACL_DH1_SIZE, 0, 0, 0,
1073     HCI_ACL_2DH3_SIZE, HCI_ACL_3DH3_SIZE, HCI_ACL_DM3_SIZE, HCI_ACL_DH3_SIZE,
1074     HCI_ACL_2DH5_SIZE, HCI_ACL_3DH5_SIZE, HCI_ACL_DM5_SIZE, HCI_ACL_DH5_SIZE
1075 };
1076 static const uint8_t  packet_type_feature_requirement_bit[] = {
1077      0, // 3 slot packets
1078      1, // 5 slot packets
1079     25, // EDR 2 mpbs
1080     26, // EDR 3 mbps
1081     39, // 3 slot EDR packts
1082     40, // 5 slot EDR packet
1083 };
1084 static const uint16_t packet_type_feature_packet_mask[] = {
1085     0x0f00, // 3 slot packets
1086     0xf000, // 5 slot packets
1087     0x1102, // EDR 2 mpbs
1088     0x2204, // EDR 3 mbps
1089     0x0300, // 3 slot EDR packts
1090     0x3000, // 5 slot EDR packet
1091 };
1092 
1093 static uint16_t hci_acl_packet_types_for_buffer_size_and_local_features(uint16_t buffer_size, uint8_t * local_supported_features){
1094     // enable packet types based on size
1095     uint16_t packet_types = 0;
1096     unsigned int i;
1097     for (i=0;i<16;i++){
1098         if (packet_type_sizes[i] == 0) continue;
1099         if (packet_type_sizes[i] <= buffer_size){
1100             packet_types |= 1 << i;
1101         }
1102     }
1103     // disable packet types due to missing local supported features
1104     for (i=0;i<sizeof(packet_type_feature_requirement_bit);i++){
1105         unsigned int bit_idx = packet_type_feature_requirement_bit[i];
1106         int feature_set = (local_supported_features[bit_idx >> 3] & (1<<(bit_idx & 7))) != 0;
1107         if (feature_set) continue;
1108         log_info("Features bit %02u is not set, removing packet types 0x%04x", bit_idx, packet_type_feature_packet_mask[i]);
1109         packet_types &= ~packet_type_feature_packet_mask[i];
1110     }
1111     // flip bits for "may not be used"
1112     packet_types ^= 0x3306;
1113     return packet_types;
1114 }
1115 
1116 uint16_t hci_usable_acl_packet_types(void){
1117     return hci_stack->packet_types;
1118 }
1119 #endif
1120 
1121 uint8_t* hci_get_outgoing_packet_buffer(void){
1122     // hci packet buffer is >= acl data packet length
1123     return hci_stack->hci_packet_buffer;
1124 }
1125 
1126 uint16_t hci_max_acl_data_packet_length(void){
1127     return hci_stack->acl_data_packet_length;
1128 }
1129 
1130 #ifdef ENABLE_CLASSIC
1131 bool hci_extended_sco_link_supported(void){
1132     // No. 31, byte 3, bit 7
1133     return (hci_stack->local_supported_features[3] & (1 << 7)) != 0;
1134 }
1135 #endif
1136 
1137 bool hci_non_flushable_packet_boundary_flag_supported(void){
1138     // No. 54, byte 6, bit 6
1139     return (hci_stack->local_supported_features[6u] & (1u << 6u)) != 0u;
1140 }
1141 
1142 static int gap_ssp_supported(void){
1143     // No. 51, byte 6, bit 3
1144     return (hci_stack->local_supported_features[6u] & (1u << 3u)) != 0u;
1145 }
1146 
1147 static int hci_classic_supported(void){
1148 #ifdef ENABLE_CLASSIC
1149     // No. 37, byte 4, bit 5, = No BR/EDR Support
1150     return (hci_stack->local_supported_features[4] & (1 << 5)) == 0;
1151 #else
1152     return 0;
1153 #endif
1154 }
1155 
1156 static int hci_le_supported(void){
1157 #ifdef ENABLE_BLE
1158     // No. 37, byte 4, bit 6 = LE Supported (Controller)
1159     return (hci_stack->local_supported_features[4u] & (1u << 6u)) != 0u;
1160 #else
1161     return 0;
1162 #endif
1163 }
1164 
1165 #ifdef ENABLE_BLE
1166 
1167 static void hci_get_own_address_for_addr_type(uint8_t own_addr_type, bd_addr_t own_addr){
1168     if (own_addr_type == BD_ADDR_TYPE_LE_PUBLIC){
1169         (void)memcpy(own_addr, hci_stack->local_bd_addr, 6);
1170     } else {
1171         (void)memcpy(own_addr, hci_stack->le_random_address, 6);
1172     }
1173 }
1174 
1175 void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr){
1176     *addr_type = hci_stack->le_own_addr_type;
1177     hci_get_own_address_for_addr_type(hci_stack->le_own_addr_type, addr);
1178 }
1179 
1180 #ifdef ENABLE_LE_PERIPHERAL
1181 void gap_le_get_own_advertisements_address(uint8_t * addr_type, bd_addr_t addr){
1182     *addr_type = hci_stack->le_advertisements_own_addr_type;
1183     hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, addr);
1184 };
1185 #endif
1186 
1187 #ifdef ENABLE_LE_CENTRAL
1188 
1189 /**
1190  * @brief Get own addr type and address used for LE connections (Central)
1191  */
1192 void gap_le_get_own_connection_address(uint8_t * addr_type, bd_addr_t addr){
1193     *addr_type = hci_stack->le_connection_own_addr_type;
1194     hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, addr);
1195 }
1196 
1197 void le_handle_advertisement_report(uint8_t *packet, uint16_t size){
1198 
1199     int offset = 3;
1200     int num_reports = packet[offset];
1201     offset += 1;
1202 
1203     int i;
1204     // log_info("HCI: handle adv report with num reports: %d", num_reports);
1205     uint8_t event[12 + LE_ADVERTISING_DATA_SIZE]; // use upper bound to avoid var size automatic var
1206     for (i=0; (i<num_reports) && (offset < size);i++){
1207         // sanity checks on data_length:
1208         uint8_t data_length = packet[offset + 8];
1209         if (data_length > LE_ADVERTISING_DATA_SIZE) return;
1210         if ((offset + 9u + data_length + 1u) > size)    return;
1211         // setup event
1212         uint8_t event_size = 10u + data_length;
1213         int pos = 0;
1214         event[pos++] = GAP_EVENT_ADVERTISING_REPORT;
1215         event[pos++] = event_size;
1216         (void)memcpy(&event[pos], &packet[offset], 1 + 1 + 6); // event type + address type + address
1217         offset += 8;
1218         pos += 8;
1219         event[pos++] = packet[offset + 1 + data_length]; // rssi
1220         event[pos++] = data_length;
1221         offset++;
1222         (void)memcpy(&event[pos], &packet[offset], data_length);
1223         pos +=    data_length;
1224         offset += data_length + 1u; // rssi
1225         hci_emit_event(event, pos, 1);
1226     }
1227 }
1228 #endif
1229 #endif
1230 
1231 #ifdef ENABLE_BLE
1232 #ifdef ENABLE_LE_PERIPHERAL
1233 static void hci_update_advertisements_enabled_for_current_roles(void){
1234     if (hci_stack->le_advertisements_enabled){
1235         // get number of active le slave connections
1236         int num_slave_connections = 0;
1237         btstack_linked_list_iterator_t it;
1238         btstack_linked_list_iterator_init(&it, &hci_stack->connections);
1239         while (btstack_linked_list_iterator_has_next(&it)){
1240             hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
1241             log_info("state %u, role %u, le_con %u", con->state, con->role, hci_is_le_connection(con));
1242             if (con->state != OPEN) continue;
1243             if (con->role  != HCI_ROLE_SLAVE) continue;
1244             if (!hci_is_le_connection(con)) continue;
1245             num_slave_connections++;
1246         }
1247         log_info("Num LE Peripheral roles: %u of %u", num_slave_connections, hci_stack->le_max_number_peripheral_connections);
1248         hci_stack->le_advertisements_enabled_for_current_roles = num_slave_connections < hci_stack->le_max_number_peripheral_connections;
1249     } else {
1250         hci_stack->le_advertisements_enabled_for_current_roles = false;
1251     }
1252 }
1253 #endif
1254 #endif
1255 
1256 #ifdef ENABLE_CLASSIC
1257 static void gap_run_set_local_name(void){
1258     hci_reserve_packet_buffer();
1259     uint8_t * packet = hci_stack->hci_packet_buffer;
1260     // construct HCI Command and send
1261     uint16_t opcode = hci_write_local_name.opcode;
1262     hci_stack->last_cmd_opcode = opcode;
1263     packet[0] = opcode & 0xff;
1264     packet[1] = opcode >> 8;
1265     packet[2] = DEVICE_NAME_LEN;
1266     memset(&packet[3], 0, DEVICE_NAME_LEN);
1267     uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1268     uint16_t bytes_to_copy = btstack_min(name_len, DEVICE_NAME_LEN);
1269     // if shorter than DEVICE_NAME_LEN, it's implicitly NULL-terminated by memset call
1270     (void)memcpy(&packet[3], hci_stack->local_name, bytes_to_copy);
1271     // expand '00:00:00:00:00:00' in name with bd_addr
1272     btstack_replace_bd_addr_placeholder(&packet[3], bytes_to_copy, hci_stack->local_bd_addr);
1273     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + DEVICE_NAME_LEN);
1274 }
1275 
1276 static void gap_run_set_eir_data(void){
1277     hci_reserve_packet_buffer();
1278     uint8_t * packet = hci_stack->hci_packet_buffer;
1279     // construct HCI Command in-place and send
1280     uint16_t opcode = hci_write_extended_inquiry_response.opcode;
1281     hci_stack->last_cmd_opcode = opcode;
1282     uint16_t offset = 0;
1283     packet[offset++] = opcode & 0xff;
1284     packet[offset++] = opcode >> 8;
1285     packet[offset++] = 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN;
1286     packet[offset++] = 0;  // FEC not required
1287     memset(&packet[offset], 0, EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1288     if (hci_stack->eir_data){
1289         // copy items and expand '00:00:00:00:00:00' in name with bd_addr
1290         ad_context_t context;
1291         for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, hci_stack->eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)) {
1292             uint8_t data_type   = ad_iterator_get_data_type(&context);
1293             uint8_t size        = ad_iterator_get_data_len(&context);
1294             const uint8_t *data = ad_iterator_get_data(&context);
1295             // copy item
1296             packet[offset++] = size + 1;
1297             packet[offset++] = data_type;
1298             memcpy(&packet[offset], data, size);
1299             // update name item
1300             if ((data_type == BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME) || (data_type == BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME)){
1301                 btstack_replace_bd_addr_placeholder(&packet[offset], size, hci_stack->local_bd_addr);
1302             }
1303             offset += size;
1304         }
1305     } else {
1306         uint16_t name_len = (uint16_t) strlen(hci_stack->local_name);
1307         uint16_t bytes_to_copy = btstack_min(name_len, EXTENDED_INQUIRY_RESPONSE_DATA_LEN - 2);
1308         packet[offset++] = bytes_to_copy + 1;
1309         packet[offset++] = BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME;
1310         (void)memcpy(&packet[6], hci_stack->local_name, bytes_to_copy);
1311         // expand '00:00:00:00:00:00' in name with bd_addr
1312         btstack_replace_bd_addr_placeholder(&packet[offset], bytes_to_copy, hci_stack->local_bd_addr);
1313     }
1314     hci_send_cmd_packet(packet, HCI_CMD_HEADER_SIZE + 1 + EXTENDED_INQUIRY_RESPONSE_DATA_LEN);
1315 }
1316 
1317 static void hci_run_gap_tasks_classic(void){
1318     if ((hci_stack->gap_tasks & GAP_TASK_SET_CLASS_OF_DEVICE) != 0) {
1319         hci_stack->gap_tasks &= ~GAP_TASK_SET_CLASS_OF_DEVICE;
1320         hci_send_cmd(&hci_write_class_of_device, hci_stack->class_of_device);
1321         return;
1322     }
1323     if ((hci_stack->gap_tasks & GAP_TASK_SET_LOCAL_NAME) != 0) {
1324         hci_stack->gap_tasks &= ~GAP_TASK_SET_LOCAL_NAME;
1325         gap_run_set_local_name();
1326         return;
1327     }
1328     if ((hci_stack->gap_tasks & GAP_TASK_SET_EIR_DATA) != 0) {
1329         hci_stack->gap_tasks &= ~GAP_TASK_SET_EIR_DATA;
1330         gap_run_set_eir_data();
1331         return;
1332     }
1333     if ((hci_stack->gap_tasks & GAP_TASK_SET_DEFAULT_LINK_POLICY) != 0) {
1334         hci_stack->gap_tasks &= ~GAP_TASK_SET_DEFAULT_LINK_POLICY;
1335         hci_send_cmd(&hci_write_default_link_policy_setting, hci_stack->default_link_policy_settings);
1336         return;
1337     }
1338     // write page scan activity
1339     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY) != 0) {
1340         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
1341         hci_send_cmd(&hci_write_page_scan_activity, hci_stack->new_page_scan_interval, hci_stack->new_page_scan_window);
1342         return;
1343     }
1344     // write page scan type
1345     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_PAGE_SCAN_TYPE) != 0) {
1346         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_PAGE_SCAN_TYPE;
1347         hci_send_cmd(&hci_write_page_scan_type, hci_stack->new_page_scan_type);
1348         return;
1349     }
1350     // send scan enable
1351     if ((hci_stack->gap_tasks & GAP_TASK_WRITE_SCAN_ENABLE) != 0) {
1352         hci_stack->gap_tasks &= ~GAP_TASK_WRITE_SCAN_ENABLE;
1353         hci_send_cmd(&hci_write_scan_enable, hci_stack->new_scan_enable_value);
1354         return;
1355     }
1356 }
1357 #endif
1358 
1359 #ifndef HAVE_HOST_CONTROLLER_API
1360 
1361 static uint32_t hci_transport_uart_get_main_baud_rate(void){
1362     if (!hci_stack->config) return 0;
1363     uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1364     // Limit baud rate for Broadcom chipsets to 3 mbps
1365     if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) && (baud_rate > 3000000)){
1366         baud_rate = 3000000;
1367     }
1368     return baud_rate;
1369 }
1370 
1371 static void hci_initialization_timeout_handler(btstack_timer_source_t * ds){
1372     UNUSED(ds);
1373 
1374     switch (hci_stack->substate){
1375         case HCI_INIT_W4_SEND_RESET:
1376             log_info("Resend HCI Reset");
1377             hci_stack->substate = HCI_INIT_SEND_RESET;
1378             hci_stack->num_cmd_packets = 1;
1379             hci_run();
1380             break;
1381         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET:
1382             log_info("Resend HCI Reset - CSR Warm Boot with Link Reset");
1383             if (hci_stack->hci_transport->reset_link){
1384                 hci_stack->hci_transport->reset_link();
1385             }
1386 
1387             /* fall through */
1388 
1389         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1390             log_info("Resend HCI Reset - CSR Warm Boot");
1391             hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1392             hci_stack->num_cmd_packets = 1;
1393             hci_run();
1394             break;
1395         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1396             if (hci_stack->hci_transport->set_baudrate){
1397                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1398                 log_info("Local baud rate change to %" PRIu32 "(timeout handler)", baud_rate);
1399                 hci_stack->hci_transport->set_baudrate(baud_rate);
1400             }
1401             // For CSR, HCI Reset is sent on new baud rate. Don't forget to reset link for H5/BCSP
1402             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
1403                 if (hci_stack->hci_transport->reset_link){
1404                     log_info("Link Reset");
1405                     hci_stack->hci_transport->reset_link();
1406                 }
1407                 hci_stack->substate = HCI_INIT_SEND_RESET_CSR_WARM_BOOT;
1408                 hci_run();
1409             }
1410             break;
1411         case HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY:
1412             // otherwise continue
1413             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1414             hci_send_cmd(&hci_read_local_supported_commands);
1415             break;
1416         default:
1417             break;
1418     }
1419 }
1420 #endif
1421 
1422 static void hci_initializing_next_state(void){
1423     hci_stack->substate = (hci_substate_t )( ((int) hci_stack->substate) + 1);
1424 }
1425 
1426 static void hci_init_done(void){
1427     // done. tell the app
1428     log_info("hci_init_done -> HCI_STATE_WORKING");
1429     hci_stack->state = HCI_STATE_WORKING;
1430     hci_emit_state();
1431 }
1432 
1433 // assumption: hci_can_send_command_packet_now() == true
1434 static void hci_initializing_run(void){
1435     log_debug("hci_initializing_run: substate %u, can send %u", hci_stack->substate, hci_can_send_command_packet_now());
1436 
1437     bool need_baud_change = false;
1438 
1439 #ifndef HAVE_HOST_CONTROLLER_API
1440     need_baud_change = hci_stack->config
1441             && hci_stack->chipset
1442             && hci_stack->chipset->set_baudrate_command
1443             && hci_stack->hci_transport->set_baudrate
1444             && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1445 #endif
1446 
1447     switch (hci_stack->substate){
1448         case HCI_INIT_SEND_RESET:
1449             hci_state_reset();
1450 
1451 #ifndef HAVE_HOST_CONTROLLER_API
1452             // prepare reset if command complete not received in 100ms
1453             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1454             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1455             btstack_run_loop_add_timer(&hci_stack->timeout);
1456 #endif
1457             // send command
1458             hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1459             hci_send_cmd(&hci_reset);
1460             break;
1461         case HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION:
1462             hci_send_cmd(&hci_read_local_version_information);
1463             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION;
1464             break;
1465         case HCI_INIT_SEND_READ_LOCAL_NAME:
1466             hci_send_cmd(&hci_read_local_name);
1467             hci_stack->substate = HCI_INIT_W4_SEND_READ_LOCAL_NAME;
1468             break;
1469 
1470 #ifndef HAVE_HOST_CONTROLLER_API
1471         case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1472             hci_state_reset();
1473             // prepare reset if command complete not received in 100ms
1474             btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1475             btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1476             btstack_run_loop_add_timer(&hci_stack->timeout);
1477             // send command
1478             hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1479             hci_send_cmd(&hci_reset);
1480             break;
1481         case HCI_INIT_SEND_RESET_ST_WARM_BOOT:
1482             hci_state_reset();
1483             hci_stack->substate = HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT;
1484             hci_send_cmd(&hci_reset);
1485             break;
1486         case HCI_INIT_SEND_BAUD_CHANGE_BCM: {
1487             uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1488             hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1489             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1490             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE_BCM;
1491             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1492             break;
1493         }
1494         case HCI_INIT_SET_BD_ADDR:
1495             log_info("Set Public BD ADDR to %s", bd_addr_to_str(hci_stack->custom_bd_addr));
1496             hci_stack->chipset->set_bd_addr_command(hci_stack->custom_bd_addr, hci_stack->hci_packet_buffer);
1497             hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1498             hci_stack->substate = HCI_INIT_W4_SET_BD_ADDR;
1499             hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1500             break;
1501         case HCI_INIT_SEND_BAUD_CHANGE:
1502             if (need_baud_change) {
1503                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1504                 hci_stack->chipset->set_baudrate_command(baud_rate, hci_stack->hci_packet_buffer);
1505                 hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1506                 hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1507                 hci_send_cmd_packet(hci_stack->hci_packet_buffer, 3u + hci_stack->hci_packet_buffer[2u]);
1508                 // STLC25000D: baudrate change happens within 0.5 s after command was send,
1509                 // use timer to update baud rate after 100 ms (knowing exactly, when command was sent is non-trivial)
1510                 if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS){
1511                     btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1512                     btstack_run_loop_add_timer(&hci_stack->timeout);
1513                }
1514                break;
1515             }
1516 
1517             /* fall through */
1518 
1519         case HCI_INIT_CUSTOM_INIT:
1520             // Custom initialization
1521             if (hci_stack->chipset && hci_stack->chipset->next_command){
1522                 hci_stack->chipset_result = (*hci_stack->chipset->next_command)(hci_stack->hci_packet_buffer);
1523                 bool send_cmd = false;
1524                 switch (hci_stack->chipset_result){
1525                     case BTSTACK_CHIPSET_VALID_COMMAND:
1526                         send_cmd = true;
1527                         hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT;
1528                         break;
1529                     case BTSTACK_CHIPSET_WARMSTART_REQUIRED:
1530                         send_cmd = true;
1531                         // CSR Warm Boot: Wait a bit, then send HCI Reset until HCI Command Complete
1532                         log_info("CSR Warm Boot");
1533                         btstack_run_loop_set_timer(&hci_stack->timeout, HCI_RESET_RESEND_TIMEOUT_MS);
1534                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1535                         btstack_run_loop_add_timer(&hci_stack->timeout);
1536                         if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO)
1537                             && hci_stack->config
1538                             && hci_stack->chipset
1539                             // && hci_stack->chipset->set_baudrate_command -- there's no such command
1540                             && hci_stack->hci_transport->set_baudrate
1541                             && hci_transport_uart_get_main_baud_rate()){
1542                             hci_stack->substate = HCI_INIT_W4_SEND_BAUD_CHANGE;
1543                         } else {
1544                            hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT_LINK_RESET;
1545                         }
1546                         break;
1547                     default:
1548                         break;
1549                 }
1550 
1551                 if (send_cmd){
1552                     int size = 3u + hci_stack->hci_packet_buffer[2u];
1553                     hci_stack->last_cmd_opcode = little_endian_read_16(hci_stack->hci_packet_buffer, 0);
1554                     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, hci_stack->hci_packet_buffer, size);
1555                     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, hci_stack->hci_packet_buffer, size);
1556                     break;
1557                 }
1558                 log_info("Init script done");
1559 
1560                 // Init script download on Broadcom chipsets causes:
1561                 if ( (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1562                    (  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION)
1563                 ||    (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA)) ){
1564 
1565                     // - baud rate to reset, restore UART baud rate if needed
1566                     if (need_baud_change) {
1567                         uint32_t baud_rate = ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_init;
1568                         log_info("Local baud rate change to %" PRIu32 " after init script (bcm)", baud_rate);
1569                         hci_stack->hci_transport->set_baudrate(baud_rate);
1570                     }
1571 
1572                     uint16_t bcm_delay_ms = 300;
1573                     // - UART may or may not be disabled during update and Controller RTS may or may not be high during this time
1574                     //   -> Work around: wait here.
1575                     log_info("BCM delay (%u ms) after init script", bcm_delay_ms);
1576                     hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_BCM_DELAY;
1577                     btstack_run_loop_set_timer(&hci_stack->timeout, bcm_delay_ms);
1578                     btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_initialization_timeout_handler);
1579                     btstack_run_loop_add_timer(&hci_stack->timeout);
1580                     break;
1581                 }
1582             }
1583             /* fall through */
1584 #endif
1585 
1586         case HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS:
1587             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS;
1588             hci_send_cmd(&hci_read_local_supported_commands);
1589             break;
1590         case HCI_INIT_READ_BD_ADDR:
1591             hci_stack->substate = HCI_INIT_W4_READ_BD_ADDR;
1592             hci_send_cmd(&hci_read_bd_addr);
1593             break;
1594         case HCI_INIT_READ_BUFFER_SIZE:
1595             // only read buffer size if supported
1596             if (hci_stack->local_supported_commands[0u] & 0x01u) {
1597                 hci_stack->substate = HCI_INIT_W4_READ_BUFFER_SIZE;
1598                 hci_send_cmd(&hci_read_buffer_size);
1599                 break;
1600             }
1601             /* fall through */
1602 
1603         case HCI_INIT_READ_LOCAL_SUPPORTED_FEATURES:
1604             hci_stack->substate = HCI_INIT_W4_READ_LOCAL_SUPPORTED_FEATURES;
1605             hci_send_cmd(&hci_read_local_supported_features);
1606             break;
1607 
1608 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
1609         case HCI_INIT_SET_CONTROLLER_TO_HOST_FLOW_CONTROL:
1610             hci_stack->substate = HCI_INIT_W4_SET_CONTROLLER_TO_HOST_FLOW_CONTROL;
1611             hci_send_cmd(&hci_set_controller_to_host_flow_control, 3);  // ACL + SCO Flow Control
1612             break;
1613         case HCI_INIT_HOST_BUFFER_SIZE:
1614             hci_stack->substate = HCI_INIT_W4_HOST_BUFFER_SIZE;
1615             hci_send_cmd(&hci_host_buffer_size, HCI_HOST_ACL_PACKET_LEN, HCI_HOST_SCO_PACKET_LEN,
1616                                                 HCI_HOST_ACL_PACKET_NUM, HCI_HOST_SCO_PACKET_NUM);
1617             break;
1618 #endif
1619 
1620         case HCI_INIT_SET_EVENT_MASK:
1621             hci_stack->substate = HCI_INIT_W4_SET_EVENT_MASK;
1622             if (hci_le_supported()){
1623                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x3FFFFFFFU);
1624             } else {
1625                 // Kensington Bluetooth 2.1 USB Dongle (CSR Chipset) returns an error for 0xffff...
1626                 hci_send_cmd(&hci_set_event_mask,0xFFFFFFFFU, 0x1FFFFFFFU);
1627             }
1628             break;
1629 
1630 #ifdef ENABLE_CLASSIC
1631         case HCI_INIT_WRITE_SIMPLE_PAIRING_MODE:
1632             if (hci_classic_supported() && gap_ssp_supported()){
1633                 hci_stack->substate = HCI_INIT_W4_WRITE_SIMPLE_PAIRING_MODE;
1634                 hci_send_cmd(&hci_write_simple_pairing_mode, hci_stack->ssp_enable);
1635                 break;
1636             }
1637             /* fall through */
1638 
1639         case HCI_INIT_WRITE_INQUIRY_MODE:
1640             if (hci_classic_supported()){
1641                 hci_stack->substate = HCI_INIT_W4_WRITE_INQUIRY_MODE;
1642                 hci_send_cmd(&hci_write_inquiry_mode, (int) hci_stack->inquiry_mode);
1643                 break;
1644             }
1645             /* fall through */
1646 
1647         case HCI_INIT_WRITE_SECURE_CONNECTIONS_HOST_ENABLE:
1648             // skip write secure connections host support if not supported or disabled
1649             if (hci_classic_supported() && hci_stack->secure_connections_enable && (hci_stack->local_supported_commands[1u] & 0x02u) != 0u) {
1650                 hci_send_cmd(&hci_write_secure_connections_host_support, 1);
1651                 hci_stack->secure_connections_active = true;
1652                 hci_stack->substate = HCI_INIT_W4_WRITE_SECURE_CONNECTIONS_HOST_ENABLE;
1653                 break;
1654             }
1655             /* fall through */
1656 
1657         case HCI_INIT_WRITE_PAGE_TIMEOUT:
1658             if (hci_classic_supported()){
1659                 hci_stack->substate = HCI_INIT_W4_WRITE_PAGE_TIMEOUT;
1660                 hci_send_cmd(&hci_write_page_timeout, 0x6000);  // ca. 15 sec
1661                 break;
1662             }
1663             /* fall through */
1664 
1665         // only sent if ENABLE_SCO_OVER_HCI is defined
1666         case HCI_INIT_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
1667             if (hci_classic_supported()){
1668                 hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
1669                 hci_send_cmd(&hci_write_synchronous_flow_control_enable, 1); // SCO tracking enabled
1670                 break;
1671             }
1672             /* fall through */
1673 
1674         case HCI_INIT_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
1675             if (hci_classic_supported()){
1676                 hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
1677                 hci_send_cmd(&hci_write_default_erroneous_data_reporting, 1);
1678                 break;
1679             }
1680             /* fall through */
1681 
1682 #if defined(ENABLE_SCO_OVER_HCI) || defined(ENABLE_SCO_OVER_PCM)
1683         // only sent if manufacturer is Broadcom and ENABLE_SCO_OVER_HCI or ENABLE_SCO_OVER_PCM is defined
1684         case HCI_INIT_BCM_WRITE_SCO_PCM_INT:
1685             if (hci_classic_supported()){
1686                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT;
1687 #ifdef ENABLE_SCO_OVER_HCI
1688                 log_info("BCM: Route SCO data via HCI transport");
1689                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 1, 0, 0, 0, 0);
1690 #endif
1691 #ifdef ENABLE_SCO_OVER_PCM
1692                 log_info("BCM: Route SCO data via PCM interface");
1693 #ifdef ENABLE_BCM_PCM_WBS
1694                 // 512 kHz bit clock for 2 channels x 16 bit x 16 kHz
1695                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 2, 0, 1, 1);
1696 #else
1697                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1698                 hci_send_cmd(&hci_bcm_write_sco_pcm_int, 0, 1, 0, 1, 1);
1699 #endif
1700 #endif
1701                 break;
1702             }
1703             /* fall through */
1704 #endif
1705 
1706 #ifdef ENABLE_SCO_OVER_PCM
1707         case HCI_INIT_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
1708             if (hci_classic_supported()){
1709                 hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
1710                 log_info("BCM: Config PCM interface for I2S");
1711 #ifdef ENABLE_BCM_PCM_WBS
1712                 // 512 kHz bit clock for 2 channels x 16 bit x 8 kHz
1713                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 2);
1714 #else
1715                 // 256 kHz bit clock for 2 channels x 16 bit x 8 kHz
1716                 hci_send_cmd(&hci_bcm_write_i2spcm_interface_param, 1, 1, 0, 1);
1717 #endif
1718                 break;
1719             }
1720             /* fall through */
1721 #endif
1722 #endif
1723 
1724 #ifdef ENABLE_BLE
1725         // LE INIT
1726         case HCI_INIT_LE_READ_BUFFER_SIZE:
1727             if (hci_le_supported()){
1728                 hci_stack->substate = HCI_INIT_W4_LE_READ_BUFFER_SIZE;
1729                 hci_send_cmd(&hci_le_read_buffer_size);
1730                 break;
1731             }
1732             /* fall through */
1733 
1734         case HCI_INIT_LE_SET_EVENT_MASK:
1735             if (hci_le_supported()){
1736                 hci_stack->substate = HCI_INIT_W4_LE_SET_EVENT_MASK;
1737                 hci_send_cmd(&hci_le_set_event_mask, 0x809FF, 0x0); // bits 0-8, 11, 19
1738                 break;
1739             }
1740             /* fall through */
1741 
1742         case HCI_INIT_WRITE_LE_HOST_SUPPORTED:
1743             if (hci_le_supported()){
1744                 // LE Supported Host = 1, Simultaneous Host = 0
1745                 hci_stack->substate = HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED;
1746                 hci_send_cmd(&hci_write_le_host_supported, 1, 0);
1747                 break;
1748             }
1749             /* fall through */
1750 
1751 #endif
1752 
1753 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
1754         case HCI_INIT_LE_READ_MAX_DATA_LENGTH:
1755             if (hci_le_supported()){
1756                 hci_stack->substate = HCI_INIT_W4_LE_READ_MAX_DATA_LENGTH;
1757                 hci_send_cmd(&hci_le_read_maximum_data_length);
1758                 break;
1759             }
1760             /* fall through */
1761 
1762         case HCI_INIT_LE_WRITE_SUGGESTED_DATA_LENGTH:
1763             if (hci_le_supported()){
1764                 hci_stack->substate = HCI_INIT_W4_LE_WRITE_SUGGESTED_DATA_LENGTH;
1765                 hci_send_cmd(&hci_le_write_suggested_default_data_length, hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
1766                 break;
1767             }
1768             /* fall through */
1769 #endif
1770 
1771 #ifdef ENABLE_LE_CENTRAL
1772         case HCI_INIT_READ_WHITE_LIST_SIZE:
1773             if (hci_le_supported()){
1774                 hci_stack->substate = HCI_INIT_W4_READ_WHITE_LIST_SIZE;
1775                 hci_send_cmd(&hci_le_read_white_list_size);
1776                 break;
1777             }
1778             /* fall through */
1779 
1780         case HCI_INIT_LE_SET_SCAN_PARAMETERS:
1781             if (hci_le_supported()){
1782                 hci_stack->substate = HCI_INIT_W4_LE_SET_SCAN_PARAMETERS;
1783                 hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window, hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
1784                 break;
1785             }
1786             /* fall through */
1787 #endif
1788 
1789         case HCI_INIT_DONE:
1790             hci_stack->substate = HCI_INIT_DONE;
1791 #ifdef ENABLE_CLASSIC
1792             // init sequence complete, check if GAP Tasks are completed
1793             if (hci_stack->gap_tasks != 0) {
1794                 hci_run_gap_tasks_classic();
1795                 break;
1796             }
1797 #endif
1798             hci_init_done();
1799             break;
1800 
1801         default:
1802             return;
1803     }
1804 }
1805 
1806 static bool hci_initializing_event_handler_command_completed(const uint8_t * packet){
1807     bool command_completed = false;
1808     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE){
1809         uint16_t opcode = little_endian_read_16(packet,3);
1810         if (opcode == hci_stack->last_cmd_opcode){
1811             command_completed = true;
1812             log_debug("Command complete for expected opcode %04x at substate %u", opcode, hci_stack->substate);
1813         } else {
1814             log_info("Command complete for different opcode %04x, expected %04x, at substate %u", opcode, hci_stack->last_cmd_opcode, hci_stack->substate);
1815         }
1816     }
1817 
1818     if (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_STATUS){
1819         uint8_t  status = packet[2];
1820         uint16_t opcode = little_endian_read_16(packet,4);
1821         if (opcode == hci_stack->last_cmd_opcode){
1822             if (status){
1823                 command_completed = true;
1824                 log_debug("Command status error 0x%02x for expected opcode %04x at substate %u", status, opcode, hci_stack->substate);
1825             } else {
1826                 log_info("Command status OK for expected opcode %04x, waiting for command complete", opcode);
1827             }
1828         } else {
1829             log_debug("Command status for opcode %04x, expected %04x", opcode, hci_stack->last_cmd_opcode);
1830         }
1831     }
1832 #ifndef HAVE_HOST_CONTROLLER_API
1833     // Vendor == CSR
1834     if ((hci_stack->substate == HCI_INIT_W4_CUSTOM_INIT) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1835         // TODO: track actual command
1836         command_completed = true;
1837     }
1838 
1839     // Vendor == Toshiba
1840     if ((hci_stack->substate == HCI_INIT_W4_SEND_BAUD_CHANGE) && (hci_event_packet_get_type(packet) == HCI_EVENT_VENDOR_SPECIFIC)){
1841         // TODO: track actual command
1842         command_completed = true;
1843         // Fix: no HCI Command Complete received, so num_cmd_packets not reset
1844         hci_stack->num_cmd_packets = 1;
1845     }
1846 #endif
1847 
1848     return command_completed;
1849 }
1850 
1851 static void hci_initializing_event_handler(const uint8_t * packet, uint16_t size){
1852 
1853     UNUSED(size);   // ok: less than 6 bytes are read from our buffer
1854 
1855     bool command_completed =  hci_initializing_event_handler_command_completed(packet);
1856 
1857 #ifndef HAVE_HOST_CONTROLLER_API
1858 
1859     // Late response (> 100 ms) for HCI Reset e.g. on Toshiba TC35661:
1860     // Command complete for HCI Reset arrives after we've resent the HCI Reset command
1861     //
1862     // HCI Reset
1863     // Timeout 100 ms
1864     // HCI Reset
1865     // Command Complete Reset
1866     // HCI Read Local Version Information
1867     // Command Complete Reset - but we expected Command Complete Read Local Version Information
1868     // hang...
1869     //
1870     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1871     if (!command_completed
1872             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1873             && (hci_stack->substate == HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION)){
1874 
1875         uint16_t opcode = little_endian_read_16(packet,3);
1876         if (opcode == hci_reset.opcode){
1877             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1878             return;
1879         }
1880     }
1881 
1882     // CSR & H5
1883     // Fix: Command Complete for HCI Reset in HCI_INIT_W4_SEND_READ_LOCAL_VERSION_INFORMATION trigger resend
1884     if (!command_completed
1885             && (hci_event_packet_get_type(packet) == HCI_EVENT_COMMAND_COMPLETE)
1886             && (hci_stack->substate == HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS)){
1887 
1888         uint16_t opcode = little_endian_read_16(packet,3);
1889         if (opcode == hci_reset.opcode){
1890             hci_stack->substate = HCI_INIT_READ_LOCAL_SUPPORTED_COMMANDS;
1891             return;
1892         }
1893     }
1894 
1895     // on CSR with BCSP/H5, the reset resend timeout leads to substate == HCI_INIT_SEND_RESET or HCI_INIT_SEND_RESET_CSR_WARM_BOOT
1896     // fix: Correct substate and behave as command below
1897     if (command_completed){
1898         switch (hci_stack->substate){
1899             case HCI_INIT_SEND_RESET:
1900                 hci_stack->substate = HCI_INIT_W4_SEND_RESET;
1901                 break;
1902             case HCI_INIT_SEND_RESET_CSR_WARM_BOOT:
1903                 hci_stack->substate = HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT;
1904                 break;
1905             default:
1906                 break;
1907         }
1908     }
1909 
1910 #endif
1911 
1912     if (!command_completed) return;
1913 
1914     bool need_baud_change = false;
1915     bool need_addr_change = false;
1916 
1917 #ifndef HAVE_HOST_CONTROLLER_API
1918     need_baud_change = hci_stack->config
1919                         && hci_stack->chipset
1920                         && hci_stack->chipset->set_baudrate_command
1921                         && hci_stack->hci_transport->set_baudrate
1922                         && ((hci_transport_config_uart_t *)hci_stack->config)->baudrate_main;
1923 
1924     need_addr_change = hci_stack->custom_bd_addr_set
1925                         && hci_stack->chipset
1926                         && hci_stack->chipset->set_bd_addr_command;
1927 #endif
1928 
1929     switch(hci_stack->substate){
1930 
1931 #ifndef HAVE_HOST_CONTROLLER_API
1932         case HCI_INIT_SEND_RESET:
1933             // on CSR with BCSP/H5, resend triggers resend of HCI Reset and leads to substate == HCI_INIT_SEND_RESET
1934             // fix: just correct substate and behave as command below
1935 
1936             /* fall through */
1937 #endif
1938 
1939         case HCI_INIT_W4_SEND_RESET:
1940             btstack_run_loop_remove_timer(&hci_stack->timeout);
1941             hci_stack->substate = HCI_INIT_SEND_READ_LOCAL_VERSION_INFORMATION;
1942             return;
1943 
1944 #ifndef HAVE_HOST_CONTROLLER_API
1945         case HCI_INIT_W4_SEND_BAUD_CHANGE:
1946             // for STLC2500D, baud rate change already happened.
1947             // for others, baud rate gets changed now
1948             if ((hci_stack->manufacturer != BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS) && need_baud_change){
1949                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1950                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change)", baud_rate);
1951                 hci_stack->hci_transport->set_baudrate(baud_rate);
1952             }
1953             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1954             return;
1955         case HCI_INIT_W4_CUSTOM_INIT_CSR_WARM_BOOT:
1956             btstack_run_loop_remove_timer(&hci_stack->timeout);
1957             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1958             return;
1959         case HCI_INIT_W4_CUSTOM_INIT:
1960             // repeat custom init
1961             hci_stack->substate = HCI_INIT_CUSTOM_INIT;
1962             return;
1963 #endif
1964 
1965         case HCI_INIT_W4_READ_LOCAL_SUPPORTED_COMMANDS:
1966             if (need_baud_change && (hci_stack->chipset_result != BTSTACK_CHIPSET_NO_INIT_SCRIPT) &&
1967               ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) ||
1968                (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_EM_MICROELECTRONIC_MARIN_SA))) {
1969                 hci_stack->substate = HCI_INIT_SEND_BAUD_CHANGE_BCM;
1970                 return;
1971             }
1972             if (need_addr_change){
1973                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1974                 return;
1975             }
1976             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1977             return;
1978 #ifndef HAVE_HOST_CONTROLLER_API
1979         case HCI_INIT_W4_SEND_BAUD_CHANGE_BCM:
1980             if (need_baud_change){
1981                 uint32_t baud_rate = hci_transport_uart_get_main_baud_rate();
1982                 log_info("Local baud rate change to %" PRIu32 "(w4_send_baud_change_bcm))", baud_rate);
1983                 hci_stack->hci_transport->set_baudrate(baud_rate);
1984             }
1985             if (need_addr_change){
1986                 hci_stack->substate = HCI_INIT_SET_BD_ADDR;
1987                 return;
1988             }
1989             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
1990             return;
1991         case HCI_INIT_W4_SET_BD_ADDR:
1992             // for STLC2500D + ATWILC3000, bd addr change only gets active after sending reset command
1993             if ((hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ST_MICROELECTRONICS)
1994             ||  (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_ATMEL_CORPORATION)){
1995                 hci_stack->substate = HCI_INIT_SEND_RESET_ST_WARM_BOOT;
1996                 return;
1997             }
1998             // skipping st warm boot
1999             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2000             return;
2001         case HCI_INIT_W4_SEND_RESET_ST_WARM_BOOT:
2002             hci_stack->substate = HCI_INIT_READ_BD_ADDR;
2003             return;
2004 #endif
2005 
2006 #ifdef ENABLE_BLE
2007         case HCI_INIT_W4_LE_READ_BUFFER_SIZE:
2008             // skip write le host if not supported (e.g. on LE only EM9301)
2009             if (hci_stack->local_supported_commands[0u] & 0x02u) break;
2010             hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
2011             return;
2012 
2013 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2014         case HCI_INIT_W4_WRITE_LE_HOST_SUPPORTED:
2015             log_info("Supported commands %x", hci_stack->local_supported_commands[0] & 0x30);
2016             if ((hci_stack->local_supported_commands[0u] & 0x30u) == 0x30u){
2017                 hci_stack->substate = HCI_INIT_LE_SET_EVENT_MASK;
2018                 return;
2019             }
2020             // explicit fall through to reduce repetitions
2021 
2022 #ifdef ENABLE_LE_CENTRAL
2023             hci_stack->substate = HCI_INIT_READ_WHITE_LIST_SIZE;
2024 #else
2025             hci_stack->substate = HCI_INIT_DONE;
2026 #endif
2027             return;
2028 #endif  /* ENABLE_LE_DATA_LENGTH_EXTENSION */
2029 
2030 #endif  /* ENABLE_BLE */
2031 
2032 #ifdef ENABLE_SCO_OVER_HCI
2033         case HCI_INIT_W4_WRITE_PAGE_TIMEOUT:
2034             // skip write synchronous flow control if not supported
2035             if (hci_stack->local_supported_commands[0] & 0x04) break;
2036             hci_stack->substate = HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE;
2037 
2038             /* fall through */
2039 
2040         case HCI_INIT_W4_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2041             // skip write default erroneous data reporting if not supported
2042             if (hci_stack->local_supported_commands[0] & 0x08) break;
2043             hci_stack->substate = HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING;
2044 
2045             /* fall through */
2046 
2047         case HCI_INIT_W4_WRITE_DEFAULT_ERRONEOUS_DATA_REPORTING:
2048             // skip bcm set sco pcm config on non-Broadcom chipsets
2049             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) break;
2050             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
2051 
2052             /* fall through */
2053 
2054         case HCI_INIT_W4_BCM_WRITE_SCO_PCM_INT:
2055             if (!hci_le_supported()){
2056                 // SKIP LE init for Classic only configuration
2057                 hci_stack->substate = HCI_INIT_DONE;
2058                 return;
2059             }
2060             hci_stack->substate = HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM;
2061             break;
2062 
2063 #else /* !ENABLE_SCO_OVER_HCI */
2064 
2065         case HCI_INIT_W4_WRITE_PAGE_TIMEOUT:
2066 #ifdef ENABLE_SCO_OVER_PCM
2067             if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION) {
2068                 hci_stack->substate = HCI_INIT_BCM_WRITE_SCO_PCM_INT;
2069                 return;
2070             }
2071 #endif
2072             /* fall through */
2073 
2074         case HCI_INIT_W4_BCM_WRITE_I2SPCM_INTERFACE_PARAM:
2075 #ifdef ENABLE_BLE
2076             if (hci_le_supported()){
2077                 hci_stack->substate = HCI_INIT_LE_READ_BUFFER_SIZE;
2078                 return;
2079             }
2080 #endif
2081             // SKIP LE init for Classic only configuration
2082             hci_stack->substate = HCI_INIT_DONE;
2083             return;
2084 #endif /* ENABLE_SCO_OVER_HCI */
2085 
2086         case HCI_INIT_DONE:
2087             // set state if we came here by fall through
2088             hci_stack->substate = HCI_INIT_DONE;
2089             return;
2090 
2091         default:
2092             break;
2093     }
2094     hci_initializing_next_state();
2095 }
2096 
2097 static void hci_handle_connection_failed(hci_connection_t * conn, uint8_t status){
2098     log_info("Outgoing connection to %s failed", bd_addr_to_str(conn->address));
2099     bd_addr_t bd_address;
2100     (void)memcpy(&bd_address, conn->address, 6);
2101 
2102 #ifdef ENABLE_CLASSIC
2103     // cache needed data
2104     int notify_dedicated_bonding_failed = conn->bonding_flags & BONDING_DEDICATED;
2105 #endif
2106 
2107     // connection failed, remove entry
2108     btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2109     btstack_memory_hci_connection_free( conn );
2110 
2111 #ifdef ENABLE_CLASSIC
2112     // notify client if dedicated bonding
2113     if (notify_dedicated_bonding_failed){
2114         log_info("hci notify_dedicated_bonding_failed");
2115         hci_emit_dedicated_bonding_result(bd_address, status);
2116     }
2117 
2118     // if authentication error, also delete link key
2119     if (status == ERROR_CODE_AUTHENTICATION_FAILURE) {
2120         gap_drop_link_key_for_bd_addr(bd_address);
2121     }
2122 #else
2123     UNUSED(status);
2124 #endif
2125 }
2126 
2127 #ifdef ENABLE_CLASSIC
2128 static void hci_handle_remote_features_page_0(hci_connection_t * conn, const uint8_t * features){
2129     // SSP Controller
2130     if (features[6] & (1 << 3)){
2131         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER;
2132     }
2133     // eSCO
2134     if (features[3] & (1<<7)){
2135         conn->remote_supported_features[0] |= 1;
2136     }
2137     // Extended features
2138     if (features[7] & (1<<7)){
2139         conn->remote_supported_features[0] |= 2;
2140     }
2141 }
2142 
2143 static void hci_handle_remote_features_page_1(hci_connection_t * conn, const uint8_t * features){
2144     // SSP Host
2145     if (features[0] & (1 << 0)){
2146         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SSP_HOST;
2147     }
2148     // SC Host
2149     if (features[0] & (1 << 3)){
2150         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_HOST;
2151     }
2152 }
2153 
2154 static void hci_handle_remote_features_page_2(hci_connection_t * conn, const uint8_t * features){
2155     // SC Controller
2156     if (features[1] & (1 << 0)){
2157         conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2158     }
2159 }
2160 
2161 static void hci_handle_remote_features_received(hci_connection_t * conn){
2162     conn->bonding_flags |= BONDING_RECEIVED_REMOTE_FEATURES;
2163     log_info("Remote features %02x, bonding flags %x", conn->remote_supported_features[0], conn->bonding_flags);
2164     if (conn->bonding_flags & BONDING_DEDICATED){
2165         conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2166     }
2167 }
2168 static bool hci_remote_sc_enabled(hci_connection_t * connection){
2169     const uint16_t sc_enabled_mask = BONDING_REMOTE_SUPPORTS_SC_HOST | BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2170     return (connection->bonding_flags & sc_enabled_mask) == sc_enabled_mask;
2171 }
2172 
2173 #endif
2174 
2175 static void handle_event_for_current_stack_state(const uint8_t * packet, uint16_t size) {
2176     // handle BT initialization
2177     if (hci_stack->state == HCI_STATE_INITIALIZING) {
2178         hci_initializing_event_handler(packet, size);
2179     }
2180 
2181     // help with BT sleep
2182     if ((hci_stack->state == HCI_STATE_FALLING_ASLEEP)
2183         && (hci_stack->substate == HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE)
2184         && HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_write_scan_enable)) {
2185         hci_initializing_next_state();
2186     }
2187 }
2188 
2189 #ifdef ENABLE_CLASSIC
2190 static void hci_handle_read_encryption_key_size_complete(hci_connection_t * conn, uint8_t encryption_key_size) {
2191     conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
2192     conn->encryption_key_size = encryption_key_size;
2193 
2194     if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) != 0) {
2195         conn->requested_security_level = LEVEL_0;
2196         hci_emit_security_level(conn->con_handle, gap_security_level_for_connection(conn));
2197         return;
2198     }
2199 
2200     // Request Authentication if not already done
2201     if ((conn->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) return;
2202     conn->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
2203 }
2204 #endif
2205 
2206 static void handle_command_complete_event(uint8_t * packet, uint16_t size){
2207     UNUSED(size);
2208 
2209     uint16_t manufacturer;
2210 #ifdef ENABLE_CLASSIC
2211     hci_con_handle_t handle;
2212     hci_connection_t * conn;
2213     uint8_t status;
2214 #endif
2215     // get num cmd packets - limit to 1 to reduce complexity
2216     hci_stack->num_cmd_packets = packet[2] ? 1 : 0;
2217 
2218     uint16_t opcode = hci_event_command_complete_get_command_opcode(packet);
2219     switch (opcode){
2220         case HCI_OPCODE_HCI_READ_LOCAL_NAME:
2221             if (packet[5]) break;
2222             // terminate, name 248 chars
2223             packet[6+248] = 0;
2224             log_info("local name: %s", &packet[6]);
2225             break;
2226         case HCI_OPCODE_HCI_READ_BUFFER_SIZE:
2227             // "The HC_ACL_Data_Packet_Length return parameter will be used to determine the size of the L2CAP segments contained in ACL Data Packets"
2228             if (hci_stack->state == HCI_STATE_INITIALIZING) {
2229                 uint16_t acl_len = little_endian_read_16(packet, 6);
2230                 uint16_t sco_len = packet[8];
2231 
2232                 // determine usable ACL/SCO payload size
2233                 hci_stack->acl_data_packet_length = btstack_min(acl_len, HCI_ACL_PAYLOAD_SIZE);
2234                 hci_stack->sco_data_packet_length = btstack_min(sco_len, HCI_ACL_PAYLOAD_SIZE);
2235 
2236                 hci_stack->acl_packets_total_num = little_endian_read_16(packet, 9);
2237                 hci_stack->sco_packets_total_num = little_endian_read_16(packet, 11);
2238 
2239                 log_info("hci_read_buffer_size: ACL size module %u -> used %u, count %u / SCO size %u, count %u",
2240                          acl_len, hci_stack->acl_data_packet_length, hci_stack->acl_packets_total_num,
2241                          hci_stack->sco_data_packet_length, hci_stack->sco_packets_total_num);
2242             }
2243             break;
2244         case HCI_OPCODE_HCI_READ_RSSI:
2245             if (packet[5] == ERROR_CODE_SUCCESS){
2246                 uint8_t event[5];
2247                 event[0] = GAP_EVENT_RSSI_MEASUREMENT;
2248                 event[1] = 3;
2249                 (void)memcpy(&event[2], &packet[6], 3);
2250                 hci_emit_event(event, sizeof(event), 1);
2251             }
2252             break;
2253 #ifdef ENABLE_BLE
2254         case HCI_OPCODE_HCI_LE_READ_BUFFER_SIZE:
2255             hci_stack->le_data_packets_length = little_endian_read_16(packet, 6);
2256             hci_stack->le_acl_packets_total_num = packet[8];
2257             // determine usable ACL payload size
2258             if (HCI_ACL_PAYLOAD_SIZE < hci_stack->le_data_packets_length){
2259                 hci_stack->le_data_packets_length = HCI_ACL_PAYLOAD_SIZE;
2260             }
2261             log_info("hci_le_read_buffer_size: size %u, count %u", hci_stack->le_data_packets_length, hci_stack->le_acl_packets_total_num);
2262             break;
2263 #endif
2264 #ifdef ENABLE_LE_DATA_LENGTH_EXTENSION
2265         case HCI_OPCODE_HCI_LE_READ_MAXIMUM_DATA_LENGTH:
2266             hci_stack->le_supported_max_tx_octets = little_endian_read_16(packet, 6);
2267             hci_stack->le_supported_max_tx_time = little_endian_read_16(packet, 8);
2268             log_info("hci_le_read_maximum_data_length: tx octets %u, tx time %u us", hci_stack->le_supported_max_tx_octets, hci_stack->le_supported_max_tx_time);
2269             break;
2270 #endif
2271 #ifdef ENABLE_LE_CENTRAL
2272         case HCI_OPCODE_HCI_LE_READ_WHITE_LIST_SIZE:
2273             hci_stack->le_whitelist_capacity = packet[6];
2274             log_info("hci_le_read_white_list_size: size %u", hci_stack->le_whitelist_capacity);
2275             break;
2276 #endif
2277         case HCI_OPCODE_HCI_READ_BD_ADDR:
2278             reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], hci_stack->local_bd_addr);
2279             log_info("Local Address, Status: 0x%02x: Addr: %s", packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE], bd_addr_to_str(hci_stack->local_bd_addr));
2280 #ifdef ENABLE_CLASSIC
2281             if (hci_stack->link_key_db){
2282                 hci_stack->link_key_db->set_local_bd_addr(hci_stack->local_bd_addr);
2283             }
2284 #endif
2285             break;
2286 #ifdef ENABLE_CLASSIC
2287         case HCI_OPCODE_HCI_WRITE_SCAN_ENABLE:
2288             hci_emit_discoverable_enabled(hci_stack->discoverable);
2289             break;
2290         case HCI_OPCODE_HCI_INQUIRY_CANCEL:
2291             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W4_CANCELLED){
2292                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2293                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2294                 hci_emit_event(event, sizeof(event), 1);
2295             }
2296             break;
2297 #endif
2298         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_FEATURES:
2299             (void)memcpy(hci_stack->local_supported_features, &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], 8);
2300 
2301 #ifdef ENABLE_CLASSIC
2302             // determine usable ACL packet types based on host buffer size and supported features
2303             hci_stack->packet_types = hci_acl_packet_types_for_buffer_size_and_local_features(HCI_ACL_PAYLOAD_SIZE, &hci_stack->local_supported_features[0]);
2304             log_info("Packet types %04x, eSCO %u", hci_stack->packet_types, hci_extended_sco_link_supported());
2305 #endif
2306             // Classic/LE
2307             log_info("BR/EDR support %u, LE support %u", hci_classic_supported(), hci_le_supported());
2308             break;
2309         case HCI_OPCODE_HCI_READ_LOCAL_VERSION_INFORMATION:
2310             manufacturer = little_endian_read_16(packet, 10);
2311             // map Cypress to Broadcom
2312             if (manufacturer  == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
2313                 log_info("Treat Cypress as Broadcom");
2314                 manufacturer = BLUETOOTH_COMPANY_ID_BROADCOM_CORPORATION;
2315                 little_endian_store_16(packet, 10, manufacturer);
2316             }
2317             hci_stack->manufacturer = manufacturer;
2318             log_info("Manufacturer: 0x%04x", hci_stack->manufacturer);
2319             break;
2320         case HCI_OPCODE_HCI_READ_LOCAL_SUPPORTED_COMMANDS:
2321             hci_stack->local_supported_commands[0] =
2322                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+14u] & 0x80u) >> 7u) |  // bit  0 = Octet 14, bit 7 / Read Buffer Size
2323                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+24u] & 0x40u) >> 5u) |  // bit  1 = Octet 24, bit 6 / Write Le Host Supported
2324                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+10u] & 0x10u) >> 2u) |  // bit  2 = Octet 10, bit 4 / Write Synchronous Flow Control Enable
2325                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+18u] & 0x08u)     )  |  // bit  3 = Octet 18, bit 3 / Write Default Erroneous Data Reporting
2326                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+34u] & 0x01u) << 4u) |  // bit  4 = Octet 34, bit 0 / LE Write Suggested Default Data Length
2327                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x08u) << 2u) |  // bit  5 = Octet 35, bit 3 / LE Read Maximum Data Length
2328                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x20u) << 1u) |  // bit  6 = Octet 35, bit 5 / LE Set Default PHY
2329                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+20u] & 0x10u) << 3u);   // bit  7 = Octet 20, bit 4 / Read Encryption Key Size
2330             hci_stack->local_supported_commands[1] =
2331                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+ 2u] & 0x40u) >> 6u) |  // bit  8 = Octet  2, bit 6 / Read Remote Extended Features
2332                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x08u) >> 2u) |  // bit  9 = Octet 32, bit 3 / Write Secure Connections Host
2333                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+35u] & 0x02u) << 1u) |  // bit 10 = Octet 35, bit 1 / LE Set Address Resolution Enable
2334                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x02u) << 2u) |  // bit 11 = Octet 32, bit 1 / Remote OOB Extended Data Request Reply
2335                 ((packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1u+32u] & 0x40u) >> 2u);   // bit 12 = Octet 32, bit 6 / Read Local OOB Extended Data command
2336             log_info("Local supported commands summary %02x - %02x", hci_stack->local_supported_commands[0],  hci_stack->local_supported_commands[1]);
2337             break;
2338 #ifdef ENABLE_CLASSIC
2339         case HCI_OPCODE_HCI_WRITE_SYNCHRONOUS_FLOW_CONTROL_ENABLE:
2340             if (packet[5]) return;
2341             hci_stack->synchronous_flow_control_enabled = 1;
2342             break;
2343         case HCI_OPCODE_HCI_READ_ENCRYPTION_KEY_SIZE:
2344             status = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE];
2345             handle = little_endian_read_16(packet, OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1);
2346             conn   = hci_connection_for_handle(handle);
2347             if (conn != NULL) {
2348                 uint8_t key_size = 0;
2349                 if (status == 0){
2350                     key_size = packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+3];
2351                     log_info("Handle %04x key Size: %u", handle, key_size);
2352                 } else {
2353                     key_size = 1;
2354                     log_info("Read Encryption Key Size failed 0x%02x-> assuming insecure connection with key size of 1", status);
2355                 }
2356                 hci_handle_read_encryption_key_size_complete(conn, key_size);
2357             }
2358             break;
2359         // assert pairing complete event is emitted.
2360         // note: for SSP, Simple Pairing Complete Event is sufficient, but we want to be more robust
2361         case HCI_OPCODE_HCI_PIN_CODE_REQUEST_NEGATIVE_REPLY:
2362         case HCI_OPCODE_HCI_USER_PASSKEY_REQUEST_NEGATIVE_REPLY:
2363         case HCI_OPCODE_HCI_USER_CONFIRMATION_REQUEST_NEGATIVE_REPLY:
2364             hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
2365             // lookup connection by gap pairing addr
2366             conn = hci_connection_for_bd_addr_and_type(hci_stack->gap_pairing_addr, BD_ADDR_TYPE_ACL);
2367             if (conn == NULL) break;
2368             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2369             break;
2370 
2371 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2372         case HCI_OPCODE_HCI_READ_LOCAL_OOB_DATA:
2373         case HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA:{
2374             uint8_t event[67];
2375             event[0] = GAP_EVENT_LOCAL_OOB_DATA;
2376             event[1] = 65;
2377             (void)memset(&event[2], 0, 65);
2378             if (packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE] == ERROR_CODE_SUCCESS){
2379                 (void)memcpy(&event[3], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+1], 32);
2380                 if (opcode == HCI_OPCODE_HCI_READ_LOCAL_EXTENDED_OOB_DATA){
2381                     event[2] = 3;
2382                     (void)memcpy(&event[35], &packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE+33], 32);
2383                 } else {
2384                     event[2] = 1;
2385                 }
2386             }
2387             hci_emit_event(event, sizeof(event), 0);
2388             break;
2389         }
2390 
2391         // note: only needed if user does not provide OOB data
2392         case HCI_OPCODE_HCI_REMOTE_OOB_DATA_REQUEST_NEGATIVE_REPLY:
2393             conn = hci_connection_for_handle(hci_stack->classic_oob_con_handle);
2394             hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
2395             if (conn == NULL) break;
2396             hci_pairing_complete(conn, ERROR_CODE_AUTHENTICATION_FAILURE);
2397             break;
2398 #endif
2399 #endif
2400         default:
2401             break;
2402     }
2403 }
2404 
2405 #ifdef ENABLE_BLE
2406 static void event_handle_le_connection_complete(const uint8_t * packet){
2407 	bd_addr_t addr;
2408 	bd_addr_type_t addr_type;
2409 	hci_connection_t * conn;
2410 
2411 	// Connection management
2412 	reverse_bd_addr(&packet[8], addr);
2413 	addr_type = (bd_addr_type_t)packet[7];
2414 	log_info("LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(addr));
2415 	conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2416 
2417 #ifdef ENABLE_LE_CENTRAL
2418 	// handle error: error is reported only to the initiator -> outgoing connection
2419 	if (packet[3]){
2420 
2421 		// handle cancelled outgoing connection
2422 		// "If the cancellation was successful then, after the Command Complete event for the LE_Create_Connection_Cancel command,
2423 		//  either an LE Connection Complete or an LE Enhanced Connection Complete event shall be generated.
2424 		//  In either case, the event shall be sent with the error code Unknown Connection Identifier (0x02)."
2425 		if (packet[3] == ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER){
2426 		    // reset state
2427             hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2428             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2429 			// get outgoing connection conn struct for direct connect
2430 			conn = gap_get_outgoing_connection();
2431 		}
2432 
2433 		// outgoing le connection establishment is done
2434 		if (conn){
2435 			// remove entry
2436 			btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
2437 			btstack_memory_hci_connection_free( conn );
2438 		}
2439 		return;
2440 	}
2441 #endif
2442 
2443 	// on success, both hosts receive connection complete event
2444 	if (packet[6] == HCI_ROLE_MASTER){
2445 #ifdef ENABLE_LE_CENTRAL
2446 		// if we're master on an le connection, it was an outgoing connection and we're done with it
2447 		// note: no hci_connection_t object exists yet for connect with whitelist
2448 		if (hci_is_le_connection_type(addr_type)){
2449 			hci_stack->le_connecting_state   = LE_CONNECTING_IDLE;
2450 			hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2451 		}
2452 #endif
2453 	} else {
2454 #ifdef ENABLE_LE_PERIPHERAL
2455 		// if we're slave, it was an incoming connection, advertisements have stopped
2456 		hci_stack->le_advertisements_active = false;
2457 #endif
2458 	}
2459 
2460 	// LE connections are auto-accepted, so just create a connection if there isn't one already
2461 	if (!conn){
2462 		conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2463 	}
2464 
2465 	// no memory, sorry.
2466 	if (!conn){
2467 		return;
2468 	}
2469 
2470 	conn->state = OPEN;
2471 	conn->role  = packet[6];
2472 	conn->con_handle             = hci_subevent_le_connection_complete_get_connection_handle(packet);
2473 	conn->le_connection_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
2474 
2475 #ifdef ENABLE_LE_PERIPHERAL
2476 	if (packet[6] == HCI_ROLE_SLAVE){
2477 		hci_update_advertisements_enabled_for_current_roles();
2478 	}
2479 #endif
2480 
2481     // init unenhanced att bearer mtu
2482     conn->att_connection.mtu = ATT_DEFAULT_MTU;
2483     conn->att_connection.mtu_exchanged = false;
2484 
2485     // TODO: store - role, peer address type, conn_interval, conn_latency, supervision timeout, master clock
2486 
2487 	// restart timer
2488 	// btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2489 	// btstack_run_loop_add_timer(&conn->timeout);
2490 
2491 	log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2492 
2493 	hci_emit_nr_connections_changed();
2494 }
2495 #endif
2496 
2497 #ifdef ENABLE_CLASSIC
2498 static bool hci_ssp_security_level_possible_for_io_cap(gap_security_level_t level, uint8_t io_cap_local, uint8_t io_cap_remote){
2499     if (io_cap_local == SSP_IO_CAPABILITY_UNKNOWN) return false;
2500     // LEVEL_4 is tested by l2cap
2501     // LEVEL 3 requires MITM protection -> check io capabilities if Authenticated is possible
2502     // @see: Core Spec v5.3, Vol 3, Part C, Table 5.7
2503     if (level >= LEVEL_3){
2504         // MITM not possible without keyboard or display
2505         if (io_cap_remote >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2506         if (io_cap_local  >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT) return false;
2507 
2508         // MITM possible if one side has keyboard and the other has keyboard or display
2509         if (io_cap_remote == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2510         if (io_cap_local  == SSP_IO_CAPABILITY_KEYBOARD_ONLY)      return true;
2511 
2512         // MITM not possible if one side has only display and other side has no keyboard
2513         if (io_cap_remote == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2514         if (io_cap_local  == SSP_IO_CAPABILITY_DISPLAY_ONLY)       return false;
2515     }
2516     // LEVEL 2 requires SSP, which is a given
2517     return true;
2518 }
2519 
2520 static bool btstack_is_null(uint8_t * data, uint16_t size){
2521     uint16_t i;
2522     for (i=0; i < size ; i++){
2523         if (data[i] != 0) {
2524             return false;
2525         }
2526     }
2527     return true;
2528 }
2529 
2530 static void hci_ssp_assess_security_on_io_cap_request(hci_connection_t * conn){
2531     // get requested security level
2532     gap_security_level_t requested_security_level = conn->requested_security_level;
2533     if (hci_stack->gap_secure_connections_only_mode){
2534         requested_security_level = LEVEL_4;
2535     }
2536 
2537     // assess security: LEVEL 4 requires SC
2538     // skip this preliminary test if remote features are not available yet to work around potential issue in ESP32 controller
2539     if ((requested_security_level == LEVEL_4) &&
2540         ((conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0) &&
2541         !hci_remote_sc_enabled(conn)){
2542         log_info("Level 4 required, but SC not supported -> abort");
2543         hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2544         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2545         return;
2546     }
2547 
2548     // assess security based on io capabilities
2549     if (conn->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
2550         // responder: fully validate io caps of both sides as well as OOB data
2551         bool security_possible = false;
2552         security_possible = hci_ssp_security_level_possible_for_io_cap(requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io);
2553 
2554 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2555         // We assume that both Controller can reach LEVEL 4, if one side has received P-192 and the other has received P-256,
2556         // so we merge the OOB data availability
2557         uint8_t have_oob_data = conn->io_cap_response_oob_data;
2558         if (conn->classic_oob_c_192 != NULL){
2559             have_oob_data |= 1;
2560         }
2561         if (conn->classic_oob_c_256 != NULL){
2562             have_oob_data |= 2;
2563         }
2564         // for up to Level 3, either P-192 as well as P-256 will do
2565         // if we don't support SC, then a) conn->classic_oob_c_256 will be NULL and b) remote should not report P-256 available
2566         // if remote does not SC, we should not receive P-256 data either
2567         if ((requested_security_level <= LEVEL_3) && (have_oob_data != 0)){
2568             security_possible = true;
2569         }
2570         // for Level 4, P-256 is needed
2571         if ((requested_security_level == LEVEL_4 && ((have_oob_data & 2) != 0))){
2572             security_possible = true;
2573         }
2574 #endif
2575 
2576         if (security_possible == false){
2577             log_info("IOCap/OOB insufficient for level %u -> abort", requested_security_level);
2578             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2579             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2580             return;
2581         }
2582     } else {
2583         // initiator: remote io cap not yet, only check if we have ability for MITM protection if requested and OOB is not supported
2584 #ifndef ENABLE_CLASSIC_PAIRING_OOB
2585 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2586         if ((conn->requested_security_level >= LEVEL_3) && (hci_stack->ssp_io_capability >= SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT)){
2587             log_info("Level 3+ required, but no input/output -> abort");
2588             hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2589             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2590             return;
2591         }
2592 #endif
2593 #endif
2594     }
2595 
2596 #ifndef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
2597     if (hci_stack->ssp_io_capability != SSP_IO_CAPABILITY_UNKNOWN){
2598         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
2599     } else {
2600         connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
2601     }
2602 #endif
2603 }
2604 
2605 #endif
2606 
2607 static void event_handler(uint8_t *packet, uint16_t size){
2608 
2609     uint16_t event_length = packet[1];
2610 
2611     // assert packet is complete
2612     if (size != (event_length + 2u)){
2613         log_error("event_handler called with packet of wrong size %d, expected %u => dropping packet", size, event_length + 2);
2614         return;
2615     }
2616 
2617     bd_addr_type_t addr_type;
2618     hci_con_handle_t handle;
2619     hci_connection_t * conn;
2620     int i;
2621     int create_connection_cmd;
2622 
2623 #ifdef ENABLE_CLASSIC
2624     hci_link_type_t link_type;
2625     bd_addr_t addr;
2626 #endif
2627 
2628     // log_info("HCI:EVENT:%02x", hci_event_packet_get_type(packet));
2629 
2630     switch (hci_event_packet_get_type(packet)) {
2631 
2632         case HCI_EVENT_COMMAND_COMPLETE:
2633             handle_command_complete_event(packet, size);
2634             break;
2635 
2636         case HCI_EVENT_COMMAND_STATUS:
2637             // get num cmd packets - limit to 1 to reduce complexity
2638             hci_stack->num_cmd_packets = packet[3] ? 1 : 0;
2639 
2640             // check command status to detected failed outgoing connections
2641             create_connection_cmd = 0;
2642 #ifdef ENABLE_CLASSIC
2643             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){
2644                 create_connection_cmd = 1;
2645             }
2646 #endif
2647 #ifdef ENABLE_LE_CENTRAL
2648             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_le_create_connection)){
2649                 create_connection_cmd = 1;
2650             }
2651 #endif
2652             if (create_connection_cmd) {
2653                 uint8_t status = hci_event_command_status_get_status(packet);
2654                 addr_type = hci_stack->outgoing_addr_type;
2655                 conn = hci_connection_for_bd_addr_and_type(hci_stack->outgoing_addr, addr_type);
2656                 log_info("command status (create connection), status %x, connection %p, addr %s, type %x", status, conn, bd_addr_to_str(hci_stack->outgoing_addr), addr_type);
2657 
2658                 // reset outgoing address info
2659                 memset(hci_stack->outgoing_addr, 0, 6);
2660                 hci_stack->outgoing_addr_type = BD_ADDR_TYPE_UNKNOWN;
2661 
2662                 // on error
2663                 if (status != ERROR_CODE_SUCCESS){
2664 #ifdef ENABLE_LE_CENTRAL
2665                     if (hci_is_le_connection_type(addr_type)){
2666                         hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
2667                         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
2668                     }
2669 #endif
2670                     // error => outgoing connection failed
2671                     if (conn != NULL){
2672                         hci_handle_connection_failed(conn, status);
2673                     }
2674                 }
2675             }
2676 
2677 #ifdef ENABLE_CLASSIC
2678             if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_inquiry)) {
2679                 uint8_t status = hci_event_command_status_get_status(packet);
2680                 log_info("command status (inquiry), status %x", status);
2681                 if (status == ERROR_CODE_SUCCESS) {
2682                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_ACTIVE;
2683                 } else {
2684                     hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2685                 }
2686             }
2687 #endif
2688             break;
2689 
2690         case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS:{
2691             if (size < 3) return;
2692             uint16_t num_handles = packet[2];
2693             if (size != (3u + num_handles * 4u)) return;
2694             uint16_t offset = 3;
2695             for (i=0; i<num_handles;i++){
2696                 handle = little_endian_read_16(packet, offset) & 0x0fffu;
2697                 offset += 2u;
2698                 uint16_t num_packets = little_endian_read_16(packet, offset);
2699                 offset += 2u;
2700 
2701                 conn = hci_connection_for_handle(handle);
2702                 if (!conn){
2703                     log_error("hci_number_completed_packet lists unused con handle %u", handle);
2704                     continue;
2705                 }
2706 
2707                 if (conn->num_packets_sent >= num_packets){
2708                     conn->num_packets_sent -= num_packets;
2709                 } else {
2710                     log_error("hci_number_completed_packets, more packet slots freed then sent.");
2711                     conn->num_packets_sent = 0;
2712                 }
2713                 // log_info("hci_number_completed_packet %u processed for handle %u, outstanding %u", num_packets, handle, conn->num_packets_sent);
2714 
2715 #ifdef ENABLE_CLASSIC
2716                 // For SCO, we do the can_send_now_check here
2717                 hci_notify_if_sco_can_send_now();
2718 #endif
2719             }
2720             break;
2721         }
2722 
2723 #ifdef ENABLE_CLASSIC
2724         case HCI_EVENT_INQUIRY_COMPLETE:
2725             if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_ACTIVE){
2726                 hci_stack->inquiry_state = GAP_INQUIRY_STATE_IDLE;
2727                 uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
2728                 hci_emit_event(event, sizeof(event), 1);
2729             }
2730             break;
2731         case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE:
2732             if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W4_COMPLETE){
2733                 hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_IDLE;
2734             }
2735             break;
2736         case HCI_EVENT_CONNECTION_REQUEST:
2737             reverse_bd_addr(&packet[2], addr);
2738             link_type = (hci_link_type_t) packet[11];
2739 
2740             // CVE-2020-26555: reject incoming connection from device with same BD ADDR
2741             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0){
2742                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2743                 bd_addr_copy(hci_stack->decline_addr, addr);
2744                 break;
2745             }
2746 
2747             if (hci_stack->gap_classic_accept_callback != NULL){
2748                 if ((*hci_stack->gap_classic_accept_callback)(addr, link_type) == 0){
2749                     hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
2750                     bd_addr_copy(hci_stack->decline_addr, addr);
2751                     break;
2752                 }
2753             }
2754 
2755             // TODO: eval COD 8-10
2756             log_info("Connection_incoming: %s, type %u", bd_addr_to_str(addr), (unsigned int) link_type);
2757             addr_type = (link_type == HCI_LINK_TYPE_ACL) ? BD_ADDR_TYPE_ACL : BD_ADDR_TYPE_SCO;
2758             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2759             if (!conn) {
2760                 conn = create_connection_for_bd_addr_and_type(addr, addr_type);
2761             }
2762             if (!conn) {
2763                 // CONNECTION REJECTED DUE TO LIMITED RESOURCES (0X0D)
2764                 hci_stack->decline_reason = ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES;
2765                 bd_addr_copy(hci_stack->decline_addr, addr);
2766                 break;
2767             }
2768             conn->role  = HCI_ROLE_SLAVE;
2769             conn->state = RECEIVED_CONNECTION_REQUEST;
2770             // store info about eSCO
2771             if (link_type == HCI_LINK_TYPE_ESCO){
2772                 conn->remote_supported_features[0] |= 1;
2773             }
2774             hci_run();
2775             break;
2776 
2777         case HCI_EVENT_CONNECTION_COMPLETE:
2778             // Connection management
2779             reverse_bd_addr(&packet[5], addr);
2780             log_info("Connection_complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2781             addr_type = BD_ADDR_TYPE_ACL;
2782             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
2783             if (conn) {
2784                 if (!packet[2]){
2785                     conn->state = OPEN;
2786                     conn->con_handle = little_endian_read_16(packet, 3);
2787 
2788                     // queue get remote feature
2789                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
2790 
2791                     // queue set supervision timeout if we're master
2792                     if ((hci_stack->link_supervision_timeout != HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT) && (conn->role == HCI_ROLE_MASTER)){
2793                         connectionSetAuthenticationFlags(conn, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
2794                     }
2795 
2796                     // restart timer
2797                     btstack_run_loop_set_timer(&conn->timeout, HCI_CONNECTION_TIMEOUT_MS);
2798                     btstack_run_loop_add_timer(&conn->timeout);
2799 
2800                     log_info("New connection: handle %u, %s", conn->con_handle, bd_addr_to_str(conn->address));
2801 
2802                     hci_emit_nr_connections_changed();
2803                 } else {
2804                     // connection failed
2805                     hci_handle_connection_failed(conn, packet[2]);
2806                 }
2807             }
2808             break;
2809 
2810         case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:
2811             reverse_bd_addr(&packet[5], addr);
2812             log_info("Synchronous Connection Complete (status=%u) %s", packet[2], bd_addr_to_str(addr));
2813             if (packet[2]){
2814                 // connection failed
2815                 break;
2816             }
2817             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2818             if (!conn) {
2819                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
2820             }
2821             if (!conn) {
2822                 break;
2823             }
2824             conn->state = OPEN;
2825             conn->con_handle = little_endian_read_16(packet, 3);
2826 
2827 #ifdef ENABLE_SCO_OVER_HCI
2828             // update SCO
2829             if (conn->address_type == BD_ADDR_TYPE_SCO && hci_stack->hci_transport && hci_stack->hci_transport->set_sco_config){
2830                 hci_stack->hci_transport->set_sco_config(hci_stack->sco_voice_setting_active, hci_number_sco_connections());
2831             }
2832             // trigger can send now
2833             if (hci_have_usb_transport()){
2834                 hci_stack->sco_can_send_now = true;
2835             }
2836 #endif
2837 #ifdef HAVE_SCO_TRANSPORT
2838             // configure sco transport
2839             if (hci_stack->sco_transport != NULL){
2840                 sco_format_t sco_format = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? SCO_FORMAT_8_BIT : SCO_FORMAT_16_BIT;
2841                 hci_stack->sco_transport->open(conn->con_handle, sco_format);
2842             }
2843 #endif
2844             break;
2845 
2846         case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE:
2847             handle = little_endian_read_16(packet, 3);
2848             conn = hci_connection_for_handle(handle);
2849             if (!conn) break;
2850             if (!packet[2]){
2851                 const uint8_t * features = &packet[5];
2852                 hci_handle_remote_features_page_0(conn, features);
2853 
2854                 // read extended features if possible
2855                 if (((hci_stack->local_supported_commands[1] & 1) != 0) && ((conn->remote_supported_features[0] & 2) != 0)) {
2856                     conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
2857                     break;
2858                 }
2859             }
2860             hci_handle_remote_features_received(conn);
2861             break;
2862 
2863         case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE:
2864             handle = little_endian_read_16(packet, 3);
2865             conn = hci_connection_for_handle(handle);
2866             if (!conn) break;
2867             // status = ok, page = 1
2868             if (!packet[2]) {
2869                 uint8_t page_number = packet[5];
2870                 uint8_t maximum_page_number = packet[6];
2871                 const uint8_t * features = &packet[7];
2872                 bool done = false;
2873                 switch (page_number){
2874                     case 1:
2875                         hci_handle_remote_features_page_1(conn, features);
2876                         if (maximum_page_number >= 2){
2877                             // get Secure Connections (Controller) from Page 2 if available
2878                             conn->bonding_flags |= BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
2879                         } else {
2880                             // otherwise, assume SC (Controller) == SC (Host)
2881                             if ((conn->bonding_flags & BONDING_REMOTE_SUPPORTS_SC_HOST) != 0){
2882                                 conn->bonding_flags |= BONDING_REMOTE_SUPPORTS_SC_CONTROLLER;
2883                             }
2884                             done = true;
2885                         }
2886                         break;
2887                     case 2:
2888                         hci_handle_remote_features_page_2(conn, features);
2889                         done = true;
2890                         break;
2891                     default:
2892                         break;
2893                 }
2894                 if (!done) break;
2895             }
2896             hci_handle_remote_features_received(conn);
2897             break;
2898 
2899         case HCI_EVENT_LINK_KEY_REQUEST:
2900 #ifndef ENABLE_EXPLICIT_LINK_KEY_REPLY
2901             hci_event_link_key_request_get_bd_addr(packet, addr);
2902             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2903             if (!conn) break;
2904 
2905             // lookup link key in db if not cached
2906             if ((conn->link_key_type == INVALID_LINK_KEY) && (hci_stack->link_key_db != NULL)){
2907                 hci_stack->link_key_db->get_link_key(conn->address, conn->link_key, &conn->link_key_type);
2908             }
2909 
2910             // response sent by hci_run()
2911             conn->authentication_flags |= AUTH_FLAG_HANDLE_LINK_KEY_REQUEST;
2912 #endif
2913             break;
2914 
2915         case HCI_EVENT_LINK_KEY_NOTIFICATION: {
2916             hci_event_link_key_request_get_bd_addr(packet, addr);
2917             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2918             if (!conn) break;
2919 
2920             hci_pairing_complete(conn, ERROR_CODE_SUCCESS);
2921 
2922             // CVE-2020-26555: ignore NULL link key
2923             // default link_key_type = INVALID_LINK_KEY asserts that NULL key won't be used for encryption
2924             if (btstack_is_null(&packet[8], 16)) break;
2925 
2926             link_key_type_t link_key_type = (link_key_type_t)packet[24];
2927             // Change Connection Encryption keeps link key type
2928             if (link_key_type != CHANGED_COMBINATION_KEY){
2929                 conn->link_key_type = link_key_type;
2930             }
2931 
2932             // cache link key. link keys stored in little-endian format for legacy reasons
2933             memcpy(&conn->link_key, &packet[8], 16);
2934 
2935             // only store link key:
2936             // - if bondable enabled
2937             if (hci_stack->bondable == false) break;
2938             // - if security level sufficient
2939             if (gap_security_level_for_link_key_type(link_key_type) < conn->requested_security_level) break;
2940             // - for SSP, also check if remote side requested bonding as well
2941             if (conn->link_key_type != COMBINATION_KEY){
2942                 bool remote_bonding = conn->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
2943                 if (!remote_bonding){
2944                     break;
2945                 }
2946             }
2947             gap_store_link_key_for_bd_addr(addr, &packet[8], conn->link_key_type);
2948             break;
2949         }
2950 
2951         case HCI_EVENT_PIN_CODE_REQUEST:
2952             hci_event_pin_code_request_get_bd_addr(packet, addr);
2953             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2954             if (!conn) break;
2955 
2956             hci_pairing_started(conn, false);
2957             // abort pairing if: non-bondable mode (pin code request is not forwarded to app)
2958             if (!hci_stack->bondable ){
2959                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2960                 hci_pairing_complete(conn, ERROR_CODE_PAIRING_NOT_ALLOWED);
2961                 hci_run();
2962                 return;
2963             }
2964             // abort pairing if: LEVEL_4 required (pin code request is not forwarded to app)
2965             if ((hci_stack->gap_secure_connections_only_mode) || (conn->requested_security_level == LEVEL_4)){
2966                 log_info("Level 4 required, but SC not supported -> abort");
2967                 conn->authentication_flags |= AUTH_FLAG_DENY_PIN_CODE_REQUEST;
2968                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
2969                 hci_run();
2970                 return;
2971             }
2972             break;
2973 
2974         case HCI_EVENT_IO_CAPABILITY_RESPONSE:
2975             hci_event_io_capability_response_get_bd_addr(packet, addr);
2976             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2977             if (!conn) break;
2978 
2979             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE);
2980             hci_pairing_started(conn, true);
2981             conn->io_cap_response_auth_req = hci_event_io_capability_response_get_authentication_requirements(packet);
2982             conn->io_cap_response_io       = hci_event_io_capability_response_get_io_capability(packet);
2983 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2984             conn->io_cap_response_oob_data = hci_event_io_capability_response_get_oob_data_present(packet);
2985 #endif
2986             break;
2987 
2988         case HCI_EVENT_IO_CAPABILITY_REQUEST:
2989             hci_event_io_capability_response_get_bd_addr(packet, addr);
2990             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
2991             if (!conn) break;
2992 
2993             hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
2994             hci_connection_timestamp(conn);
2995             hci_pairing_started(conn, true);
2996             break;
2997 
2998 #ifdef ENABLE_CLASSIC_PAIRING_OOB
2999         case HCI_EVENT_REMOTE_OOB_DATA_REQUEST:
3000             hci_event_remote_oob_data_request_get_bd_addr(packet, addr);
3001             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3002             if (!conn) break;
3003 
3004             hci_connection_timestamp(conn);
3005 
3006             hci_pairing_started(conn, true);
3007 
3008             connectionSetAuthenticationFlags(conn, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
3009             break;
3010 #endif
3011 
3012         case HCI_EVENT_USER_CONFIRMATION_REQUEST:
3013             hci_event_user_confirmation_request_get_bd_addr(packet, addr);
3014             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3015             if (!conn) break;
3016             if (hci_ssp_security_level_possible_for_io_cap(conn->requested_security_level, hci_stack->ssp_io_capability, conn->io_cap_response_io)) {
3017                 if (hci_stack->ssp_auto_accept){
3018                     hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
3019                 };
3020             } else {
3021                 hci_pairing_complete(conn, ERROR_CODE_INSUFFICIENT_SECURITY);
3022                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
3023                 // don't forward event to app
3024                 hci_run();
3025                 return;
3026             }
3027             break;
3028 
3029         case HCI_EVENT_USER_PASSKEY_REQUEST:
3030             // Pairing using Passkey results in MITM protection. If Level 4 is required, support for SC is validated on IO Cap Request
3031             if (hci_stack->ssp_auto_accept){
3032                 hci_add_connection_flags_for_flipped_bd_addr(&packet[2], AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
3033             };
3034             break;
3035 
3036         case HCI_EVENT_MODE_CHANGE:
3037             handle = hci_event_mode_change_get_handle(packet);
3038             conn = hci_connection_for_handle(handle);
3039             if (!conn) break;
3040             conn->connection_mode = hci_event_mode_change_get_mode(packet);
3041             log_info("HCI_EVENT_MODE_CHANGE, handle 0x%04x, mode %u", handle, conn->connection_mode);
3042             break;
3043 #endif
3044 
3045         case HCI_EVENT_ENCRYPTION_CHANGE:
3046             handle = hci_event_encryption_change_get_connection_handle(packet);
3047             conn = hci_connection_for_handle(handle);
3048             if (!conn) break;
3049             if (hci_event_encryption_change_get_status(packet) == 0u) {
3050                 uint8_t encryption_enabled = hci_event_encryption_change_get_encryption_enabled(packet);
3051                 if (encryption_enabled){
3052                     if (hci_is_le_connection(conn)){
3053                         // For LE, we accept connection as encrypted
3054                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_ENCRYPTED;
3055                     }
3056 #ifdef ENABLE_CLASSIC
3057                     else {
3058 
3059                         // dedicated bonding: send result and disconnect
3060                         if (conn->bonding_flags & BONDING_DEDICATED){
3061                             conn->bonding_flags &= ~BONDING_DEDICATED;
3062                             conn->bonding_flags |= BONDING_DISCONNECT_DEDICATED_DONE;
3063                             conn->bonding_status = packet[2];
3064                             break;
3065                         }
3066 
3067                         // Detect Secure Connection -> Legacy Connection Downgrade Attack (BIAS)
3068                         bool sc_used_during_pairing = gap_secure_connection_for_link_key_type(conn->link_key_type) != 0;
3069                         bool connected_uses_aes_ccm = encryption_enabled == 2;
3070                         if (hci_stack->secure_connections_active && sc_used_during_pairing && !connected_uses_aes_ccm){
3071                             log_info("SC during pairing, but only E0 now -> abort");
3072                             conn->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
3073                             break;
3074                         }
3075 
3076                         // if AES-CCM is used, authentication used SC -> authentication was mutual and we can skip explicit authentication
3077                         if (connected_uses_aes_ccm){
3078                             conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3079                         }
3080 
3081 #ifdef ENABLE_TESTING_SUPPORT
3082                         // work around for issue with PTS dongle
3083                         conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3084 #endif
3085 
3086                         if ((hci_stack->local_supported_commands[0] & 0x80) != 0){
3087                             // For Classic, we need to validate encryption key size first, if possible (== supported by Controller)
3088                             conn->bonding_flags |= BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
3089                         } else {
3090                             // if not, pretend everything is perfect
3091                             hci_handle_read_encryption_key_size_complete(conn, 16);
3092                         }
3093                     }
3094 #endif
3095                 } else {
3096                     conn->authentication_flags &= ~AUTH_FLAG_CONNECTION_ENCRYPTED;
3097                 }
3098             }
3099 
3100             break;
3101 
3102 #ifdef ENABLE_CLASSIC
3103         case HCI_EVENT_AUTHENTICATION_COMPLETE_EVENT:
3104             handle = hci_event_authentication_complete_get_connection_handle(packet);
3105             conn = hci_connection_for_handle(handle);
3106             if (!conn) break;
3107 
3108             // clear authentication active flag
3109             conn->bonding_flags &= ~BONDING_SENT_AUTHENTICATE_REQUEST;
3110             hci_pairing_complete(conn, hci_event_authentication_complete_get_status(packet));
3111 
3112             // authenticated only if auth status == 0
3113             if (hci_event_authentication_complete_get_status(packet) == 0){
3114                 // authenticated
3115                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3116 
3117                 // If not already encrypted, start encryption
3118                 if ((conn->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0){
3119                     conn->bonding_flags |= BONDING_SEND_ENCRYPTION_REQUEST;
3120                     break;
3121                 }
3122             }
3123 
3124             // emit updated security level
3125             hci_emit_security_level(handle, gap_security_level_for_connection(conn));
3126             break;
3127 
3128         case HCI_EVENT_SIMPLE_PAIRING_COMPLETE:
3129             hci_event_simple_pairing_complete_get_bd_addr(packet, addr);
3130             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
3131             if (!conn) break;
3132 
3133             // treat successfully paired connection as authenticated
3134             if (hci_event_simple_pairing_complete_get_status(packet) == ERROR_CODE_SUCCESS){
3135                 conn->authentication_flags |= AUTH_FLAG_CONNECTION_AUTHENTICATED;
3136             }
3137 
3138             hci_pairing_complete(conn, hci_event_simple_pairing_complete_get_status(packet));
3139             break;
3140 #endif
3141 
3142         // HCI_EVENT_DISCONNECTION_COMPLETE
3143         // has been split, to first notify stack before shutting connection down
3144         // see end of function, too.
3145         case HCI_EVENT_DISCONNECTION_COMPLETE:
3146             if (packet[2]) break;   // status != 0
3147             handle = little_endian_read_16(packet, 3);
3148             // drop outgoing ACL fragments if it is for closed connection and release buffer if tx not active
3149             if (hci_stack->acl_fragmentation_total_size > 0u) {
3150                 if (handle == READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer)){
3151                     int release_buffer = hci_stack->acl_fragmentation_tx_active == 0u;
3152                     log_info("drop fragmented ACL data for closed connection, release buffer %u", release_buffer);
3153                     hci_stack->acl_fragmentation_total_size = 0;
3154                     hci_stack->acl_fragmentation_pos = 0;
3155                     if (release_buffer){
3156                         hci_release_packet_buffer();
3157                     }
3158                 }
3159             }
3160 
3161             conn = hci_connection_for_handle(handle);
3162             if (!conn) break;
3163 #ifdef ENABLE_CLASSIC
3164             // pairing failed if it was ongoing
3165             hci_pairing_complete(conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
3166 #endif
3167 
3168             // emit dedicatd bonding event
3169             if (conn->bonding_flags & BONDING_EMIT_COMPLETE_ON_DISCONNECT){
3170                 hci_emit_dedicated_bonding_result(conn->address, conn->bonding_status);
3171             }
3172 
3173             // mark connection for shutdown, stop timers, reset state
3174             conn->state = RECEIVED_DISCONNECTION_COMPLETE;
3175             hci_connection_stop_timer(conn);
3176             hci_connection_init(conn);
3177 
3178 #ifdef ENABLE_BLE
3179 #ifdef ENABLE_LE_PERIPHERAL
3180             // re-enable advertisements for le connections if active
3181             if (hci_is_le_connection(conn)){
3182                 hci_update_advertisements_enabled_for_current_roles();
3183             }
3184 #endif
3185 #endif
3186             break;
3187 
3188         case HCI_EVENT_HARDWARE_ERROR:
3189             log_error("Hardware Error: 0x%02x", packet[2]);
3190             if (hci_stack->hardware_error_callback){
3191                 (*hci_stack->hardware_error_callback)(packet[2]);
3192             } else {
3193                 // if no special requests, just reboot stack
3194                 hci_power_control_off();
3195                 hci_power_control_on();
3196             }
3197             break;
3198 
3199 #ifdef ENABLE_CLASSIC
3200         case HCI_EVENT_ROLE_CHANGE:
3201             if (packet[2]) break;   // status != 0
3202             reverse_bd_addr(&packet[3], addr);
3203             addr_type = BD_ADDR_TYPE_ACL;
3204             conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
3205             if (!conn) break;
3206             conn->role = packet[9];
3207             break;
3208 #endif
3209 
3210         case HCI_EVENT_TRANSPORT_PACKET_SENT:
3211             // release packet buffer only for asynchronous transport and if there are not further fragements
3212             if (hci_transport_synchronous()) {
3213                 log_error("Synchronous HCI Transport shouldn't send HCI_EVENT_TRANSPORT_PACKET_SENT");
3214                 return; // instead of break: to avoid re-entering hci_run()
3215             }
3216             hci_stack->acl_fragmentation_tx_active = 0;
3217             if (hci_stack->acl_fragmentation_total_size) break;
3218             hci_release_packet_buffer();
3219 
3220             // L2CAP receives this event via the hci_emit_event below
3221 
3222 #ifdef ENABLE_CLASSIC
3223             // For SCO, we do the can_send_now_check here
3224             hci_notify_if_sco_can_send_now();
3225 #endif
3226             break;
3227 
3228 #ifdef ENABLE_CLASSIC
3229         case HCI_EVENT_SCO_CAN_SEND_NOW:
3230             // For SCO, we do the can_send_now_check here
3231             hci_stack->sco_can_send_now = true;
3232             hci_notify_if_sco_can_send_now();
3233             return;
3234 
3235         // explode inquriy results for easier consumption
3236         case HCI_EVENT_INQUIRY_RESULT:
3237         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
3238         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
3239             gap_inquiry_explode(packet, size);
3240             break;
3241 #endif
3242 
3243 #ifdef ENABLE_BLE
3244         case HCI_EVENT_LE_META:
3245             switch (packet[2]){
3246 #ifdef ENABLE_LE_CENTRAL
3247                 case HCI_SUBEVENT_LE_ADVERTISING_REPORT:
3248                     // log_info("advertising report received");
3249                     if (!hci_stack->le_scanning_enabled) break;
3250                     le_handle_advertisement_report(packet, size);
3251                     break;
3252 #endif
3253                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
3254 					event_handle_le_connection_complete(packet);
3255                     break;
3256 
3257                 // log_info("LE buffer size: %u, count %u", little_endian_read_16(packet,6), packet[8]);
3258                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
3259                     handle = hci_subevent_le_connection_update_complete_get_connection_handle(packet);
3260                     conn = hci_connection_for_handle(handle);
3261                     if (!conn) break;
3262                     conn->le_connection_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
3263                     break;
3264 
3265                 case HCI_SUBEVENT_LE_REMOTE_CONNECTION_PARAMETER_REQUEST:
3266                     // connection
3267                     handle = hci_subevent_le_remote_connection_parameter_request_get_connection_handle(packet);
3268                     conn = hci_connection_for_handle(handle);
3269                     if (conn) {
3270                         // read arguments
3271                         uint16_t le_conn_interval_min   = hci_subevent_le_remote_connection_parameter_request_get_interval_min(packet);
3272                         uint16_t le_conn_interval_max   = hci_subevent_le_remote_connection_parameter_request_get_interval_max(packet);
3273                         uint16_t le_conn_latency        = hci_subevent_le_remote_connection_parameter_request_get_latency(packet);
3274                         uint16_t le_supervision_timeout = hci_subevent_le_remote_connection_parameter_request_get_timeout(packet);
3275 
3276                         // validate against current connection parameter range
3277                         le_connection_parameter_range_t existing_range;
3278                         gap_get_connection_parameter_range(&existing_range);
3279                         int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout);
3280                         if (update_parameter){
3281                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_REPLY;
3282                             conn->le_conn_interval_min = le_conn_interval_min;
3283                             conn->le_conn_interval_max = le_conn_interval_max;
3284                             conn->le_conn_latency = le_conn_latency;
3285                             conn->le_supervision_timeout = le_supervision_timeout;
3286                         } else {
3287                             conn->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NEGATIVE_REPLY;
3288                         }
3289                     }
3290                     break;
3291 #ifdef ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS
3292                 case HCI_SUBEVENT_LE_DATA_LENGTH_CHANGE:
3293                     handle = hci_subevent_le_data_length_change_get_connection_handle(packet);
3294                     conn = hci_connection_for_handle(handle);
3295                     if (conn) {
3296                         conn->le_max_tx_octets = hci_subevent_le_data_length_change_get_max_tx_octets(packet);
3297                     }
3298                     break;
3299 #endif
3300                 default:
3301                     break;
3302             }
3303             break;
3304 #endif
3305         case HCI_EVENT_VENDOR_SPECIFIC:
3306             // Vendor specific commands often create vendor specific event instead of num completed packets
3307             // To avoid getting stuck as num_cmds_packets is zero, reset it to 1 for controllers with this behaviour
3308             switch (hci_stack->manufacturer){
3309                 case BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO:
3310                     hci_stack->num_cmd_packets = 1;
3311                     break;
3312                 default:
3313                     break;
3314             }
3315             break;
3316         default:
3317             break;
3318     }
3319 
3320     handle_event_for_current_stack_state(packet, size);
3321 
3322     // notify upper stack
3323 	hci_emit_event(packet, size, 0);   // don't dump, already happened in packet handler
3324 
3325     // moved here to give upper stack a chance to close down everything with hci_connection_t intact
3326     if ((hci_event_packet_get_type(packet) == HCI_EVENT_DISCONNECTION_COMPLETE) && (packet[2] == 0)){
3327 		handle = little_endian_read_16(packet, 3);
3328 		hci_connection_t * aConn = hci_connection_for_handle(handle);
3329 		// discard connection if app did not trigger a reconnect in the event handler
3330 		if (aConn && aConn->state == RECEIVED_DISCONNECTION_COMPLETE){
3331 			hci_shutdown_connection(aConn);
3332 		}
3333     }
3334 
3335 	// execute main loop
3336 	hci_run();
3337 }
3338 
3339 #ifdef ENABLE_CLASSIC
3340 
3341 #ifdef ENABLE_SCO_OVER_HCI
3342 static void sco_tx_timeout_handler(btstack_timer_source_t * ts);
3343 static void sco_schedule_tx(hci_connection_t * conn);
3344 
3345 static void sco_tx_timeout_handler(btstack_timer_source_t * ts){
3346     log_debug("SCO TX Timeout");
3347     hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) btstack_run_loop_get_timer_context(ts);
3348     hci_connection_t * conn = hci_connection_for_handle(con_handle);
3349     if (!conn) return;
3350 
3351     // trigger send
3352     conn->sco_tx_ready = 1;
3353     // extra packet if CVSD but SCO buffer is too short
3354     if (((hci_stack->sco_voice_setting_active & 0x03) != 0x03) && (hci_stack->sco_data_packet_length < 123)){
3355         conn->sco_tx_ready++;
3356     }
3357     hci_notify_if_sco_can_send_now();
3358 }
3359 
3360 
3361 #define SCO_TX_AFTER_RX_MS (6)
3362 
3363 static void sco_schedule_tx(hci_connection_t * conn){
3364 
3365     uint32_t now = btstack_run_loop_get_time_ms();
3366     uint32_t sco_tx_ms = conn->sco_rx_ms + SCO_TX_AFTER_RX_MS;
3367     int time_delta_ms = sco_tx_ms - now;
3368 
3369     btstack_timer_source_t * timer = (conn->sco_rx_count & 1) ? &conn->timeout : &conn->timeout_sco;
3370 
3371     // log_error("SCO TX at %u in %u", (int) sco_tx_ms, time_delta_ms);
3372     btstack_run_loop_remove_timer(timer);
3373     btstack_run_loop_set_timer(timer, time_delta_ms);
3374     btstack_run_loop_set_timer_context(timer, (void *) (uintptr_t) conn->con_handle);
3375     btstack_run_loop_set_timer_handler(timer, &sco_tx_timeout_handler);
3376     btstack_run_loop_add_timer(timer);
3377 }
3378 #endif
3379 
3380 static void sco_handler(uint8_t * packet, uint16_t size){
3381     // lookup connection struct
3382     hci_con_handle_t con_handle = READ_SCO_CONNECTION_HANDLE(packet);
3383     hci_connection_t * conn     = hci_connection_for_handle(con_handle);
3384     if (!conn) return;
3385 
3386 #ifdef ENABLE_SCO_OVER_HCI
3387     // CSR 8811 prefixes 60 byte SCO packet in transparent mode with 20 zero bytes -> skip first 20 payload bytes
3388     if (hci_stack->manufacturer == BLUETOOTH_COMPANY_ID_CAMBRIDGE_SILICON_RADIO){
3389         if ((size == 83) && ((hci_stack->sco_voice_setting_active & 0x03) == 0x03)){
3390             packet[2] = 0x3c;
3391             memmove(&packet[3], &packet[23], 63);
3392             size = 63;
3393         }
3394     }
3395 
3396     if (hci_have_usb_transport()){
3397         // Nothing to do
3398     } else {
3399         // log_debug("sco flow %u, handle 0x%04x, packets sent %u, bytes send %u", hci_stack->synchronous_flow_control_enabled, (int) con_handle, conn->num_packets_sent, conn->num_sco_bytes_sent);
3400         if (hci_stack->synchronous_flow_control_enabled == 0){
3401             uint32_t now = btstack_run_loop_get_time_ms();
3402 
3403             if (!conn->sco_rx_valid){
3404                 // ignore first 10 packets
3405                 conn->sco_rx_count++;
3406                 // log_debug("sco rx count %u", conn->sco_rx_count);
3407                 if (conn->sco_rx_count == 10) {
3408                     // use first timestamp as is and pretent it just started
3409                     conn->sco_rx_ms = now;
3410                     conn->sco_rx_valid = 1;
3411                     conn->sco_rx_count = 0;
3412                     sco_schedule_tx(conn);
3413                 }
3414             } else {
3415                 // track expected arrival timme
3416                 conn->sco_rx_count++;
3417                 conn->sco_rx_ms += 7;
3418                 int delta = (int32_t) (now - conn->sco_rx_ms);
3419                 if (delta > 0){
3420                     conn->sco_rx_ms++;
3421                 }
3422                 // log_debug("sco rx %u", conn->sco_rx_ms);
3423                 sco_schedule_tx(conn);
3424             }
3425         }
3426     }
3427 #endif
3428 
3429     // deliver to app
3430     if (hci_stack->sco_packet_handler) {
3431         hci_stack->sco_packet_handler(HCI_SCO_DATA_PACKET, 0, packet, size);
3432     }
3433 
3434 #ifdef HAVE_SCO_TRANSPORT
3435     // We can send one packet for each received packet
3436     conn->sco_tx_ready++;
3437     hci_notify_if_sco_can_send_now();
3438 #endif
3439 
3440 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
3441     conn->num_packets_completed++;
3442     hci_stack->host_completed_packets = 1;
3443     hci_run();
3444 #endif
3445 }
3446 #endif
3447 
3448 static void packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
3449     hci_dump_packet(packet_type, 1, packet, size);
3450     switch (packet_type) {
3451         case HCI_EVENT_PACKET:
3452             event_handler(packet, size);
3453             break;
3454         case HCI_ACL_DATA_PACKET:
3455             acl_handler(packet, size);
3456             break;
3457 #ifdef ENABLE_CLASSIC
3458         case HCI_SCO_DATA_PACKET:
3459             sco_handler(packet, size);
3460             break;
3461 #endif
3462         default:
3463             break;
3464     }
3465 }
3466 
3467 /**
3468  * @brief Add event packet handler.
3469  */
3470 void hci_add_event_handler(btstack_packet_callback_registration_t * callback_handler){
3471     btstack_linked_list_add_tail(&hci_stack->event_handlers, (btstack_linked_item_t*) callback_handler);
3472 }
3473 
3474 
3475 /** Register HCI packet handlers */
3476 void hci_register_acl_packet_handler(btstack_packet_handler_t handler){
3477     hci_stack->acl_packet_handler = handler;
3478 }
3479 
3480 #ifdef ENABLE_CLASSIC
3481 /**
3482  * @brief Registers a packet handler for SCO data. Used for HSP and HFP profiles.
3483  */
3484 void hci_register_sco_packet_handler(btstack_packet_handler_t handler){
3485     hci_stack->sco_packet_handler = handler;
3486 }
3487 #endif
3488 
3489 static void hci_state_reset(void){
3490     // no connections yet
3491     hci_stack->connections = NULL;
3492 
3493     // keep discoverable/connectable as this has been requested by the client(s)
3494     // hci_stack->discoverable = 0;
3495     // hci_stack->connectable = 0;
3496     // hci_stack->bondable = 1;
3497     // hci_stack->own_addr_type = 0;
3498 
3499     // buffer is free
3500     hci_stack->hci_packet_buffer_reserved = false;
3501 
3502     // no pending cmds
3503     hci_stack->decline_reason = 0;
3504 
3505     hci_stack->secure_connections_active = false;
3506 
3507 #ifdef ENABLE_CLASSIC
3508     hci_stack->inquiry_lap = GAP_IAC_GENERAL_INQUIRY;
3509     hci_stack->gap_tasks =
3510             GAP_TASK_SET_DEFAULT_LINK_POLICY |
3511             GAP_TASK_SET_CLASS_OF_DEVICE |
3512             GAP_TASK_SET_LOCAL_NAME |
3513             GAP_TASK_SET_EIR_DATA |
3514             GAP_TASK_WRITE_SCAN_ENABLE;
3515 #endif
3516 
3517 #ifdef ENABLE_CLASSIC_PAIRING_OOB
3518     hci_stack->classic_read_local_oob_data = true;
3519     hci_stack->classic_oob_con_handle = HCI_CON_HANDLE_INVALID;
3520 #endif
3521 
3522     // LE
3523 #ifdef ENABLE_BLE
3524     memset(hci_stack->le_random_address, 0, 6);
3525     hci_stack->le_random_address_set = 0;
3526 #endif
3527 #ifdef ENABLE_LE_CENTRAL
3528     hci_stack->le_scanning_active  = false;
3529     hci_stack->le_connecting_state = LE_CONNECTING_IDLE;
3530     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
3531     hci_stack->le_whitelist_capacity = 0;
3532 #endif
3533 #ifdef ENABLE_LE_PERIPHERAL
3534     hci_stack->le_advertisements_active = false;
3535     if ((hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_PARAMS_SET) != 0){
3536         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
3537     }
3538     if (hci_stack->le_advertisements_data != NULL){
3539         hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
3540     }
3541 #endif
3542 }
3543 
3544 #ifdef ENABLE_CLASSIC
3545 /**
3546  * @brief Configure Bluetooth hardware control. Has to be called before power on.
3547  */
3548 void hci_set_link_key_db(btstack_link_key_db_t const * link_key_db){
3549     // store and open remote device db
3550     hci_stack->link_key_db = link_key_db;
3551     if (hci_stack->link_key_db) {
3552         hci_stack->link_key_db->open();
3553     }
3554 }
3555 #endif
3556 
3557 void hci_init(const hci_transport_t *transport, const void *config){
3558 
3559 #ifdef HAVE_MALLOC
3560     if (!hci_stack) {
3561         hci_stack = (hci_stack_t*) malloc(sizeof(hci_stack_t));
3562     }
3563 #else
3564     hci_stack = &hci_stack_static;
3565 #endif
3566     memset(hci_stack, 0, sizeof(hci_stack_t));
3567 
3568     // reference to use transport layer implementation
3569     hci_stack->hci_transport = transport;
3570 
3571     // reference to used config
3572     hci_stack->config = config;
3573 
3574     // setup pointer for outgoing packet buffer
3575     hci_stack->hci_packet_buffer = &hci_stack->hci_packet_buffer_data[HCI_OUTGOING_PRE_BUFFER_SIZE];
3576 
3577     // max acl payload size defined in config.h
3578     hci_stack->acl_data_packet_length = HCI_ACL_PAYLOAD_SIZE;
3579 
3580     // register packet handlers with transport
3581     transport->register_packet_handler(&packet_handler);
3582 
3583     hci_stack->state = HCI_STATE_OFF;
3584 
3585     // class of device
3586     hci_stack->class_of_device = 0x007a020c; // Smartphone
3587 
3588     // bondable by default
3589     hci_stack->bondable = 1;
3590 
3591 #ifdef ENABLE_CLASSIC
3592     // classic name
3593     hci_stack->local_name = default_classic_name;
3594 
3595     // Master slave policy
3596     hci_stack->master_slave_policy = 1;
3597 
3598     // Allow Role Switch
3599     hci_stack->allow_role_switch = 1;
3600 
3601     // Default / minimum security level = 2
3602     hci_stack->gap_security_level = LEVEL_2;
3603 
3604     // Default Security Mode 4
3605     hci_stack->gap_security_mode = GAP_SECURITY_MODE_4;
3606 
3607     // Errata-11838 mandates 7 bytes for GAP Security Level 1-3
3608     hci_stack->gap_required_encyrption_key_size = 7;
3609 
3610     // Link Supervision Timeout
3611     hci_stack->link_supervision_timeout = HCI_LINK_SUPERVISION_TIMEOUT_DEFAULT;
3612 
3613 #endif
3614 
3615     // Secure Simple Pairing default: enable, no I/O capabilities, general bonding, mitm not required, auto accept
3616     hci_stack->ssp_enable = 1;
3617     hci_stack->ssp_io_capability = SSP_IO_CAPABILITY_NO_INPUT_NO_OUTPUT;
3618     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
3619     hci_stack->ssp_auto_accept = 1;
3620 
3621     // Secure Connections: enable (requires support from Controller)
3622     hci_stack->secure_connections_enable = true;
3623 
3624     // voice setting - signed 16 bit pcm data with CVSD over the air
3625     hci_stack->sco_voice_setting = 0x60;
3626 
3627 #ifdef ENABLE_LE_CENTRAL
3628     // connection parameter to use for outgoing connections
3629     hci_stack->le_connection_scan_interval = 0x0060;   // 60ms
3630     hci_stack->le_connection_scan_window  = 0x0030;    // 30ms
3631     hci_stack->le_connection_interval_min = 0x0008;    // 10 ms
3632     hci_stack->le_connection_interval_max = 0x0018;    // 30 ms
3633     hci_stack->le_connection_latency      = 4;         // 4
3634     hci_stack->le_supervision_timeout     = 0x0048;    // 720 ms
3635     hci_stack->le_minimum_ce_length       = 2;         // 1.25 ms
3636     hci_stack->le_maximum_ce_length       = 0x0030;    // 30 ms
3637 
3638     // default LE Scanning
3639     hci_stack->le_scan_type     =   0x1; // active
3640     hci_stack->le_scan_interval = 0x1e0; // 300 ms
3641     hci_stack->le_scan_window   =  0x30; //  30 ms
3642 #endif
3643 
3644 #ifdef ENABLE_LE_PERIPHERAL
3645     hci_stack->le_max_number_peripheral_connections = 1; // only single connection as peripheral
3646 #endif
3647 
3648     // connection parameter range used to answer connection parameter update requests in l2cap
3649     hci_stack->le_connection_parameter_range.le_conn_interval_min =          6;
3650     hci_stack->le_connection_parameter_range.le_conn_interval_max =       3200;
3651     hci_stack->le_connection_parameter_range.le_conn_latency_min =           0;
3652     hci_stack->le_connection_parameter_range.le_conn_latency_max =         500;
3653     hci_stack->le_connection_parameter_range.le_supervision_timeout_min =   10;
3654     hci_stack->le_connection_parameter_range.le_supervision_timeout_max = 3200;
3655 
3656     hci_state_reset();
3657 }
3658 
3659 void hci_deinit(void){
3660 #ifdef HAVE_MALLOC
3661     if (hci_stack) {
3662         free(hci_stack);
3663     }
3664 #endif
3665     hci_stack = NULL;
3666 
3667 #ifdef ENABLE_CLASSIC
3668     disable_l2cap_timeouts = 0;
3669 #endif
3670 }
3671 
3672 /**
3673  * @brief Configure Bluetooth chipset driver. Has to be called before power on, or right after receiving the local version information
3674  */
3675 void hci_set_chipset(const btstack_chipset_t *chipset_driver){
3676     hci_stack->chipset = chipset_driver;
3677 
3678     // reset chipset driver - init is also called on power_up
3679     if (hci_stack->chipset && hci_stack->chipset->init){
3680         hci_stack->chipset->init(hci_stack->config);
3681     }
3682 }
3683 
3684 /**
3685  * @brief Configure Bluetooth hardware control. Has to be called after hci_init() but before power on.
3686  */
3687 void hci_set_control(const btstack_control_t *hardware_control){
3688     // references to used control implementation
3689     hci_stack->control = hardware_control;
3690     // init with transport config
3691     hardware_control->init(hci_stack->config);
3692 }
3693 
3694 void hci_close(void){
3695 
3696 #ifdef ENABLE_CLASSIC
3697     // close remote device db
3698     if (hci_stack->link_key_db) {
3699         hci_stack->link_key_db->close();
3700     }
3701 #endif
3702 
3703     btstack_linked_list_iterator_t lit;
3704     btstack_linked_list_iterator_init(&lit, &hci_stack->connections);
3705     while (btstack_linked_list_iterator_has_next(&lit)){
3706         // cancel all l2cap connections by emitting dicsconnection complete before shutdown (free) connection
3707         hci_connection_t * connection = (hci_connection_t*) btstack_linked_list_iterator_next(&lit);
3708         hci_emit_disconnection_complete(connection->con_handle, 0x16); // terminated by local host
3709         hci_shutdown_connection(connection);
3710     }
3711 
3712     hci_power_control(HCI_POWER_OFF);
3713 
3714 #ifdef HAVE_MALLOC
3715     free(hci_stack);
3716 #endif
3717     hci_stack = NULL;
3718 }
3719 
3720 #ifdef HAVE_SCO_TRANSPORT
3721 void hci_set_sco_transport(const btstack_sco_transport_t *sco_transport){
3722     hci_stack->sco_transport = sco_transport;
3723     sco_transport->register_packet_handler(&packet_handler);
3724 }
3725 #endif
3726 
3727 #ifdef ENABLE_CLASSIC
3728 void gap_set_required_encryption_key_size(uint8_t encryption_key_size){
3729     // validate ranage and set
3730     if (encryption_key_size < 7)  return;
3731     if (encryption_key_size > 16) return;
3732     hci_stack->gap_required_encyrption_key_size = encryption_key_size;
3733 }
3734 
3735 uint8_t gap_set_security_mode(gap_security_mode_t security_mode){
3736     if ((security_mode == GAP_SECURITY_MODE_4) || (security_mode == GAP_SECURITY_MODE_2)){
3737         hci_stack->gap_security_mode = security_mode;
3738         return ERROR_CODE_SUCCESS;
3739     } else {
3740         return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
3741     }
3742 }
3743 
3744 gap_security_mode_t gap_get_security_mode(void){
3745     return hci_stack->gap_security_mode;
3746 }
3747 
3748 void gap_set_security_level(gap_security_level_t security_level){
3749     hci_stack->gap_security_level = security_level;
3750 }
3751 
3752 gap_security_level_t gap_get_security_level(void){
3753     if (hci_stack->gap_secure_connections_only_mode){
3754         return LEVEL_4;
3755     }
3756     return hci_stack->gap_security_level;
3757 }
3758 
3759 void gap_set_minimal_service_security_level(gap_security_level_t security_level){
3760     hci_stack->gap_minimal_service_security_level = security_level;
3761 }
3762 
3763 void gap_set_secure_connections_only_mode(bool enable){
3764     hci_stack->gap_secure_connections_only_mode = enable;
3765 }
3766 
3767 bool gap_get_secure_connections_only_mode(void){
3768     return hci_stack->gap_secure_connections_only_mode;
3769 }
3770 #endif
3771 
3772 #ifdef ENABLE_CLASSIC
3773 void gap_set_class_of_device(uint32_t class_of_device){
3774     hci_stack->class_of_device = class_of_device;
3775     hci_stack->gap_tasks |= GAP_TASK_SET_CLASS_OF_DEVICE;
3776     hci_run();
3777 }
3778 
3779 void gap_set_default_link_policy_settings(uint16_t default_link_policy_settings){
3780     hci_stack->default_link_policy_settings = default_link_policy_settings;
3781     hci_stack->gap_tasks |= GAP_TASK_SET_DEFAULT_LINK_POLICY;
3782     hci_run();
3783 }
3784 
3785 void gap_set_allow_role_switch(bool allow_role_switch){
3786     hci_stack->allow_role_switch = allow_role_switch ? 1 : 0;
3787 }
3788 
3789 uint8_t hci_get_allow_role_switch(void){
3790     return  hci_stack->allow_role_switch;
3791 }
3792 
3793 void gap_set_link_supervision_timeout(uint16_t link_supervision_timeout){
3794     hci_stack->link_supervision_timeout = link_supervision_timeout;
3795 }
3796 
3797 void hci_disable_l2cap_timeout_check(void){
3798     disable_l2cap_timeouts = 1;
3799 }
3800 #endif
3801 
3802 #ifndef HAVE_HOST_CONTROLLER_API
3803 // Set Public BD ADDR - passed on to Bluetooth chipset if supported in bt_control_h
3804 void hci_set_bd_addr(bd_addr_t addr){
3805     (void)memcpy(hci_stack->custom_bd_addr, addr, 6);
3806     hci_stack->custom_bd_addr_set = 1;
3807 }
3808 #endif
3809 
3810 // State-Module-Driver overview
3811 // state                    module  low-level
3812 // HCI_STATE_OFF             off      close
3813 // HCI_STATE_INITIALIZING,   on       open
3814 // HCI_STATE_WORKING,        on       open
3815 // HCI_STATE_HALTING,        on       open
3816 // HCI_STATE_SLEEPING,    off/sleep   close
3817 // HCI_STATE_FALLING_ASLEEP  on       open
3818 
3819 static int hci_power_control_on(void){
3820 
3821     // power on
3822     int err = 0;
3823     if (hci_stack->control && hci_stack->control->on){
3824         err = (*hci_stack->control->on)();
3825     }
3826     if (err){
3827         log_error( "POWER_ON failed");
3828         hci_emit_hci_open_failed();
3829         return err;
3830     }
3831 
3832     // int chipset driver
3833     if (hci_stack->chipset && hci_stack->chipset->init){
3834         hci_stack->chipset->init(hci_stack->config);
3835     }
3836 
3837     // init transport
3838     if (hci_stack->hci_transport->init){
3839         hci_stack->hci_transport->init(hci_stack->config);
3840     }
3841 
3842     // open transport
3843     err = hci_stack->hci_transport->open();
3844     if (err){
3845         log_error( "HCI_INIT failed, turning Bluetooth off again");
3846         if (hci_stack->control && hci_stack->control->off){
3847             (*hci_stack->control->off)();
3848         }
3849         hci_emit_hci_open_failed();
3850         return err;
3851     }
3852     return 0;
3853 }
3854 
3855 static void hci_power_control_off(void){
3856 
3857     log_info("hci_power_control_off");
3858 
3859     // close low-level device
3860     hci_stack->hci_transport->close();
3861 
3862     log_info("hci_power_control_off - hci_transport closed");
3863 
3864     // power off
3865     if (hci_stack->control && hci_stack->control->off){
3866         (*hci_stack->control->off)();
3867     }
3868 
3869     log_info("hci_power_control_off - control closed");
3870 
3871     hci_stack->state = HCI_STATE_OFF;
3872 }
3873 
3874 static void hci_power_control_sleep(void){
3875 
3876     log_info("hci_power_control_sleep");
3877 
3878 #if 0
3879     // don't close serial port during sleep
3880 
3881     // close low-level device
3882     hci_stack->hci_transport->close(hci_stack->config);
3883 #endif
3884 
3885     // sleep mode
3886     if (hci_stack->control && hci_stack->control->sleep){
3887         (*hci_stack->control->sleep)();
3888     }
3889 
3890     hci_stack->state = HCI_STATE_SLEEPING;
3891 }
3892 
3893 static int hci_power_control_wake(void){
3894 
3895     log_info("hci_power_control_wake");
3896 
3897     // wake on
3898     if (hci_stack->control && hci_stack->control->wake){
3899         (*hci_stack->control->wake)();
3900     }
3901 
3902 #if 0
3903     // open low-level device
3904     int err = hci_stack->hci_transport->open(hci_stack->config);
3905     if (err){
3906         log_error( "HCI_INIT failed, turning Bluetooth off again");
3907         if (hci_stack->control && hci_stack->control->off){
3908             (*hci_stack->control->off)();
3909         }
3910         hci_emit_hci_open_failed();
3911         return err;
3912     }
3913 #endif
3914 
3915     return 0;
3916 }
3917 
3918 static void hci_power_transition_to_initializing(void){
3919     // set up state machine
3920     hci_stack->num_cmd_packets = 1; // assume that one cmd can be sent
3921     hci_stack->hci_packet_buffer_reserved = false;
3922     hci_stack->state = HCI_STATE_INITIALIZING;
3923     hci_stack->substate = HCI_INIT_SEND_RESET;
3924 }
3925 
3926 // returns error
3927 static int hci_power_control_state_off(HCI_POWER_MODE power_mode){
3928     int err;
3929     switch (power_mode){
3930         case HCI_POWER_ON:
3931             err = hci_power_control_on();
3932             if (err != 0) {
3933                 log_error("hci_power_control_on() error %d", err);
3934                 return err;
3935             }
3936             hci_power_transition_to_initializing();
3937             break;
3938         case HCI_POWER_OFF:
3939             // do nothing
3940             break;
3941         case HCI_POWER_SLEEP:
3942             // do nothing (with SLEEP == OFF)
3943             break;
3944         default:
3945             btstack_assert(false);
3946             break;
3947     }
3948     return ERROR_CODE_SUCCESS;
3949 }
3950 
3951 static int hci_power_control_state_initializing(HCI_POWER_MODE power_mode){
3952     switch (power_mode){
3953         case HCI_POWER_ON:
3954             // do nothing
3955             break;
3956         case HCI_POWER_OFF:
3957             // no connections yet, just turn it off
3958             hci_power_control_off();
3959             break;
3960         case HCI_POWER_SLEEP:
3961             // no connections yet, just turn it off
3962             hci_power_control_sleep();
3963             break;
3964         default:
3965             btstack_assert(false);
3966             break;
3967     }
3968     return ERROR_CODE_SUCCESS;
3969 }
3970 
3971 static int hci_power_control_state_working(HCI_POWER_MODE power_mode) {
3972     switch (power_mode){
3973         case HCI_POWER_ON:
3974             // do nothing
3975             break;
3976         case HCI_POWER_OFF:
3977             // see hci_run
3978             hci_stack->state = HCI_STATE_HALTING;
3979             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
3980             break;
3981         case HCI_POWER_SLEEP:
3982             // see hci_run
3983             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
3984             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
3985             break;
3986         default:
3987             btstack_assert(false);
3988             break;
3989     }
3990     return ERROR_CODE_SUCCESS;
3991 }
3992 
3993 static int hci_power_control_state_halting(HCI_POWER_MODE power_mode) {
3994     switch (power_mode){
3995         case HCI_POWER_ON:
3996             hci_power_transition_to_initializing();
3997             break;
3998         case HCI_POWER_OFF:
3999             // do nothing
4000             break;
4001         case HCI_POWER_SLEEP:
4002             // see hci_run
4003             hci_stack->state = HCI_STATE_FALLING_ASLEEP;
4004             hci_stack->substate = HCI_FALLING_ASLEEP_DISCONNECT;
4005             break;
4006         default:
4007             btstack_assert(false);
4008             break;
4009     }
4010     return ERROR_CODE_SUCCESS;
4011 }
4012 
4013 static int hci_power_control_state_falling_asleep(HCI_POWER_MODE power_mode) {
4014     switch (power_mode){
4015         case HCI_POWER_ON:
4016             hci_power_transition_to_initializing();
4017             break;
4018         case HCI_POWER_OFF:
4019             // see hci_run
4020             hci_stack->state = HCI_STATE_HALTING;
4021             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
4022             break;
4023         case HCI_POWER_SLEEP:
4024             // do nothing
4025             break;
4026         default:
4027             btstack_assert(false);
4028             break;
4029     }
4030     return ERROR_CODE_SUCCESS;
4031 }
4032 
4033 static int hci_power_control_state_sleeping(HCI_POWER_MODE power_mode) {
4034     int err;
4035     switch (power_mode){
4036         case HCI_POWER_ON:
4037             err = hci_power_control_wake();
4038             if (err) return err;
4039             hci_power_transition_to_initializing();
4040             break;
4041         case HCI_POWER_OFF:
4042             hci_stack->state = HCI_STATE_HALTING;
4043             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_NO_TIMER;
4044             break;
4045         case HCI_POWER_SLEEP:
4046             // do nothing
4047             break;
4048         default:
4049             btstack_assert(false);
4050             break;
4051     }
4052     return ERROR_CODE_SUCCESS;
4053 }
4054 
4055 int hci_power_control(HCI_POWER_MODE power_mode){
4056     log_info("hci_power_control: %d, current mode %u", power_mode, hci_stack->state);
4057     int err = 0;
4058     switch (hci_stack->state){
4059         case HCI_STATE_OFF:
4060             err = hci_power_control_state_off(power_mode);
4061             break;
4062         case HCI_STATE_INITIALIZING:
4063             err = hci_power_control_state_initializing(power_mode);
4064             break;
4065         case HCI_STATE_WORKING:
4066             err = hci_power_control_state_working(power_mode);
4067             break;
4068         case HCI_STATE_HALTING:
4069             err = hci_power_control_state_halting(power_mode);
4070             break;
4071         case HCI_STATE_FALLING_ASLEEP:
4072             err = hci_power_control_state_falling_asleep(power_mode);
4073             break;
4074         case HCI_STATE_SLEEPING:
4075             err = hci_power_control_state_sleeping(power_mode);
4076             break;
4077         default:
4078             btstack_assert(false);
4079             break;
4080     }
4081     if (err != 0){
4082         return err;
4083     }
4084 
4085     // create internal event
4086 	hci_emit_state();
4087 
4088 	// trigger next/first action
4089 	hci_run();
4090 
4091     return 0;
4092 }
4093 
4094 
4095 #ifdef ENABLE_CLASSIC
4096 
4097 static void hci_update_scan_enable(void){
4098     // 2 = page scan, 1 = inq scan
4099     hci_stack->new_scan_enable_value  = (hci_stack->connectable << 1) | hci_stack->discoverable;
4100     hci_stack->gap_tasks |= GAP_TASK_WRITE_SCAN_ENABLE;
4101     hci_run();
4102 }
4103 
4104 void gap_discoverable_control(uint8_t enable){
4105     if (enable) enable = 1; // normalize argument
4106 
4107     if (hci_stack->discoverable == enable){
4108         hci_emit_discoverable_enabled(hci_stack->discoverable);
4109         return;
4110     }
4111 
4112     hci_stack->discoverable = enable;
4113     hci_update_scan_enable();
4114 }
4115 
4116 void gap_connectable_control(uint8_t enable){
4117     if (enable) enable = 1; // normalize argument
4118 
4119     // don't emit event
4120     if (hci_stack->connectable == enable) return;
4121 
4122     hci_stack->connectable = enable;
4123     hci_update_scan_enable();
4124 }
4125 #endif
4126 
4127 void gap_local_bd_addr(bd_addr_t address_buffer){
4128     (void)memcpy(address_buffer, hci_stack->local_bd_addr, 6);
4129 }
4130 
4131 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4132 static void hci_host_num_completed_packets(void){
4133 
4134     // create packet manually as arrays are not supported and num_commands should not get reduced
4135     hci_reserve_packet_buffer();
4136     uint8_t * packet = hci_get_outgoing_packet_buffer();
4137 
4138     uint16_t size = 0;
4139     uint16_t num_handles = 0;
4140     packet[size++] = 0x35;
4141     packet[size++] = 0x0c;
4142     size++;  // skip param len
4143     size++;  // skip num handles
4144 
4145     // add { handle, packets } entries
4146     btstack_linked_item_t * it;
4147     for (it = (btstack_linked_item_t *) hci_stack->connections; it ; it = it->next){
4148         hci_connection_t * connection = (hci_connection_t *) it;
4149         if (connection->num_packets_completed){
4150             little_endian_store_16(packet, size, connection->con_handle);
4151             size += 2;
4152             little_endian_store_16(packet, size, connection->num_packets_completed);
4153             size += 2;
4154             //
4155             num_handles++;
4156             connection->num_packets_completed = 0;
4157         }
4158     }
4159 
4160     packet[2] = size - 3;
4161     packet[3] = num_handles;
4162 
4163     hci_stack->host_completed_packets = 0;
4164 
4165     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
4166     hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
4167 
4168     // release packet buffer for synchronous transport implementations
4169     if (hci_transport_synchronous()){
4170         hci_release_packet_buffer();
4171         hci_emit_transport_packet_sent();
4172     }
4173 }
4174 #endif
4175 
4176 static void hci_halting_timeout_handler(btstack_timer_source_t * ds){
4177     UNUSED(ds);
4178     hci_stack->substate = HCI_HALTING_CLOSE;
4179     // allow packet handlers to defer final shutdown
4180     hci_emit_state();
4181     hci_run();
4182 }
4183 
4184 static bool hci_run_acl_fragments(void){
4185     if (hci_stack->acl_fragmentation_total_size > 0u) {
4186         hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(hci_stack->hci_packet_buffer);
4187         hci_connection_t *connection = hci_connection_for_handle(con_handle);
4188         if (connection) {
4189             if (hci_can_send_prepared_acl_packet_now(con_handle)){
4190                 hci_send_acl_packet_fragments(connection);
4191                 return true;
4192             }
4193         } else {
4194             // connection gone -> discard further fragments
4195             log_info("hci_run: fragmented ACL packet no connection -> discard fragment");
4196             hci_stack->acl_fragmentation_total_size = 0;
4197             hci_stack->acl_fragmentation_pos = 0;
4198         }
4199     }
4200     return false;
4201 }
4202 
4203 #ifdef ENABLE_CLASSIC
4204 static bool hci_run_general_gap_classic(void){
4205 
4206     // assert stack is working and classic is active
4207     if (hci_classic_supported() == false)      return false;
4208     if (hci_stack->state != HCI_STATE_WORKING) return false;
4209 
4210     // decline incoming connections
4211     if (hci_stack->decline_reason){
4212         uint8_t reason = hci_stack->decline_reason;
4213         hci_stack->decline_reason = 0;
4214         hci_send_cmd(&hci_reject_connection_request, hci_stack->decline_addr, reason);
4215         return true;
4216     }
4217 
4218     if (hci_stack->gap_tasks != 0){
4219         hci_run_gap_tasks_classic();
4220         return true;
4221     }
4222 
4223     // start/stop inquiry
4224     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)){
4225         uint8_t duration = hci_stack->inquiry_state;
4226         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_ACTIVE;
4227         hci_send_cmd(&hci_inquiry, hci_stack->inquiry_lap, duration, 0);
4228         return true;
4229     }
4230     if (hci_stack->inquiry_state == GAP_INQUIRY_STATE_W2_CANCEL){
4231         hci_stack->inquiry_state = GAP_INQUIRY_STATE_W4_CANCELLED;
4232         hci_send_cmd(&hci_inquiry_cancel);
4233         return true;
4234     }
4235     // remote name request
4236     if (hci_stack->remote_name_state == GAP_REMOTE_NAME_STATE_W2_SEND){
4237         hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W4_COMPLETE;
4238         hci_send_cmd(&hci_remote_name_request, hci_stack->remote_name_addr,
4239                      hci_stack->remote_name_page_scan_repetition_mode, 0, hci_stack->remote_name_clock_offset);
4240         return true;
4241     }
4242 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4243     // Local OOB data
4244     if (hci_stack->classic_read_local_oob_data){
4245         hci_stack->classic_read_local_oob_data = false;
4246         if (hci_stack->local_supported_commands[1] & 0x10u){
4247             hci_send_cmd(&hci_read_local_extended_oob_data);
4248         } else {
4249             hci_send_cmd(&hci_read_local_oob_data);
4250         }
4251     }
4252 #endif
4253     // pairing
4254     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE){
4255         uint8_t state = hci_stack->gap_pairing_state;
4256         uint8_t pin_code[16];
4257         switch (state){
4258             case GAP_PAIRING_STATE_SEND_PIN:
4259                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4260                 memset(pin_code, 0, 16);
4261                 memcpy(pin_code, hci_stack->gap_pairing_input.gap_pairing_pin, hci_stack->gap_pairing_pin_len);
4262                 hci_send_cmd(&hci_pin_code_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_pin_len, pin_code);
4263                 break;
4264             case GAP_PAIRING_STATE_SEND_PIN_NEGATIVE:
4265                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4266                 hci_send_cmd(&hci_pin_code_request_negative_reply, hci_stack->gap_pairing_addr);
4267                 break;
4268             case GAP_PAIRING_STATE_SEND_PASSKEY:
4269                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4270                 hci_send_cmd(&hci_user_passkey_request_reply, hci_stack->gap_pairing_addr, hci_stack->gap_pairing_input.gap_pairing_passkey);
4271                 break;
4272             case GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE:
4273                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4274                 hci_send_cmd(&hci_user_passkey_request_negative_reply, hci_stack->gap_pairing_addr);
4275                 break;
4276             case GAP_PAIRING_STATE_SEND_CONFIRMATION:
4277                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_IDLE;
4278                 hci_send_cmd(&hci_user_confirmation_request_reply, hci_stack->gap_pairing_addr);
4279                 break;
4280             case GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE:
4281                 hci_stack->gap_pairing_state = GAP_PAIRING_STATE_WAIT_FOR_COMMAND_COMPLETE;
4282                 hci_send_cmd(&hci_user_confirmation_request_negative_reply, hci_stack->gap_pairing_addr);
4283                 break;
4284             default:
4285                 break;
4286         }
4287         return true;
4288     }
4289     return false;
4290 }
4291 #endif
4292 
4293 #ifdef ENABLE_BLE
4294 static bool hci_run_general_gap_le(void){
4295 
4296     // advertisements, active scanning, and creating connections requires random address to be set if using private address
4297 
4298     if (hci_stack->state != HCI_STATE_WORKING) return false;
4299     if ( (hci_stack->le_own_addr_type != BD_ADDR_TYPE_LE_PUBLIC) && (hci_stack->le_random_address_set == 0u) ) return false;
4300 
4301 
4302     // Phase 1: collect what to stop
4303 
4304     bool scanning_stop = false;
4305     bool connecting_stop = false;
4306     bool advertising_stop = false;
4307 
4308 #ifndef ENABLE_LE_CENTRAL
4309     UNUSED(scanning_stop);
4310     UNUSED(connecting_stop);
4311 #endif
4312 #ifndef ENABLE_LE_PERIPHERAL
4313     UNUSED(advertising_stop);
4314 #endif
4315 
4316     // check if whitelist needs modification
4317     bool whitelist_modification_pending = false;
4318     btstack_linked_list_iterator_t lit;
4319     btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4320     while (btstack_linked_list_iterator_has_next(&lit)){
4321         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4322         if (entry->state & (LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER)){
4323             whitelist_modification_pending = true;
4324             break;
4325         }
4326     }
4327     // check if resolving list needs modification
4328     bool resolving_list_modification_pending = false;
4329 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4330     bool resolving_list_supported = (hci_stack->local_supported_commands[1] & (1 << 2)) != 0;
4331 	if (resolving_list_supported && hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_DONE){
4332         resolving_list_modification_pending = true;
4333     }
4334 #endif
4335 
4336 #ifdef ENABLE_LE_CENTRAL
4337     // scanning control
4338     if (hci_stack->le_scanning_active) {
4339         // stop if:
4340         // - parameter change required
4341         // - it's disabled
4342         // - whitelist change required but used for scanning
4343         // - resolving list modified
4344         bool scanning_uses_whitelist = (hci_stack->le_scan_filter_policy & 1) == 1;
4345         if ((hci_stack->le_scanning_param_update) ||
4346             !hci_stack->le_scanning_enabled ||
4347             scanning_uses_whitelist ||
4348             resolving_list_modification_pending){
4349 
4350             scanning_stop = true;
4351         }
4352     }
4353 #endif
4354 
4355 #ifdef ENABLE_LE_CENTRAL
4356     // connecting control
4357     bool connecting_with_whitelist;
4358     switch (hci_stack->le_connecting_state){
4359         case LE_CONNECTING_DIRECT:
4360         case LE_CONNECTING_WHITELIST:
4361             // stop connecting if:
4362             // - connecting uses white and whitelist modification pending
4363             // - if it got disabled
4364             // - resolving list modified
4365             connecting_with_whitelist = hci_stack->le_connecting_state == LE_CONNECTING_WHITELIST;
4366             if ((connecting_with_whitelist && whitelist_modification_pending) ||
4367                 (hci_stack->le_connecting_request == LE_CONNECTING_IDLE) ||
4368                 resolving_list_modification_pending) {
4369 
4370                 connecting_stop = true;
4371             }
4372             break;
4373         default:
4374             break;
4375     }
4376 #endif
4377 
4378 #ifdef ENABLE_LE_PERIPHERAL
4379     // le advertisement control
4380     if (hci_stack->le_advertisements_active){
4381         // stop if:
4382         // - parameter change required
4383         // - it's disabled
4384         // - whitelist change required but used for advertisement filter policy
4385         // - resolving list modified
4386         bool advertising_uses_whitelist = hci_stack->le_advertisements_filter_policy != 0;
4387         bool advertising_change = (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS) != 0;
4388         if (advertising_change ||
4389             (hci_stack->le_advertisements_enabled_for_current_roles == 0) ||
4390             (advertising_uses_whitelist & whitelist_modification_pending) ||
4391             resolving_list_modification_pending) {
4392 
4393             advertising_stop = true;
4394         }
4395     }
4396 #endif
4397 
4398 
4399     // Phase 2: stop everything that should be off during modifications
4400 
4401 #ifdef ENABLE_LE_CENTRAL
4402     if (scanning_stop){
4403         hci_stack->le_scanning_active = false;
4404         hci_send_cmd(&hci_le_set_scan_enable, 0, 0);
4405         return true;
4406     }
4407 #endif
4408 
4409 #ifdef ENABLE_LE_CENTRAL
4410     if (connecting_stop){
4411         hci_send_cmd(&hci_le_create_connection_cancel);
4412         return true;
4413     }
4414 #endif
4415 
4416 #ifdef ENABLE_LE_PERIPHERAL
4417     if (advertising_stop){
4418         hci_stack->le_advertisements_active = false;
4419         hci_send_cmd(&hci_le_set_advertise_enable, 0);
4420         return true;
4421     }
4422 #endif
4423 
4424     // Phase 3: modify
4425 
4426 #ifdef ENABLE_LE_CENTRAL
4427     if (hci_stack->le_scanning_param_update){
4428         hci_stack->le_scanning_param_update = false;
4429         hci_send_cmd(&hci_le_set_scan_parameters, hci_stack->le_scan_type, hci_stack->le_scan_interval, hci_stack->le_scan_window,
4430                      hci_stack->le_own_addr_type, hci_stack->le_scan_filter_policy);
4431         return true;
4432     }
4433 #endif
4434 
4435 #ifdef ENABLE_LE_PERIPHERAL
4436     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_PARAMS){
4437         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_PARAMS;
4438         hci_stack->le_advertisements_own_addr_type = hci_stack->le_own_addr_type;
4439         hci_send_cmd(&hci_le_set_advertising_parameters,
4440                      hci_stack->le_advertisements_interval_min,
4441                      hci_stack->le_advertisements_interval_max,
4442                      hci_stack->le_advertisements_type,
4443                      hci_stack->le_advertisements_own_addr_type,
4444                      hci_stack->le_advertisements_direct_address_type,
4445                      hci_stack->le_advertisements_direct_address,
4446                      hci_stack->le_advertisements_channel_map,
4447                      hci_stack->le_advertisements_filter_policy);
4448         return true;
4449     }
4450     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_ADV_DATA){
4451         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
4452         uint8_t adv_data_clean[31];
4453         memset(adv_data_clean, 0, sizeof(adv_data_clean));
4454         (void)memcpy(adv_data_clean, hci_stack->le_advertisements_data,
4455                      hci_stack->le_advertisements_data_len);
4456         btstack_replace_bd_addr_placeholder(adv_data_clean, hci_stack->le_advertisements_data_len, hci_stack->local_bd_addr);
4457         hci_send_cmd(&hci_le_set_advertising_data, hci_stack->le_advertisements_data_len, adv_data_clean);
4458         return true;
4459     }
4460     if (hci_stack->le_advertisements_todo & LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA){
4461         hci_stack->le_advertisements_todo &= ~LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
4462         uint8_t scan_data_clean[31];
4463         memset(scan_data_clean, 0, sizeof(scan_data_clean));
4464         (void)memcpy(scan_data_clean, hci_stack->le_scan_response_data,
4465                      hci_stack->le_scan_response_data_len);
4466         btstack_replace_bd_addr_placeholder(scan_data_clean, hci_stack->le_scan_response_data_len, hci_stack->local_bd_addr);
4467         hci_send_cmd(&hci_le_set_scan_response_data, hci_stack->le_scan_response_data_len, scan_data_clean);
4468         return true;
4469     }
4470 #endif
4471 
4472 
4473 #ifdef ENABLE_LE_CENTRAL
4474     // if connect with whitelist was active and is not cancelled yet, wait until next time
4475     if (hci_stack->le_connecting_state == LE_CONNECTING_CANCEL) return false;
4476 #endif
4477 
4478     // LE Whitelist Management
4479     if (whitelist_modification_pending){
4480         // add/remove entries
4481         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4482         while (btstack_linked_list_iterator_has_next(&lit)){
4483             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
4484 			if (entry->state & LE_WHITELIST_REMOVE_FROM_CONTROLLER){
4485 				entry->state &= ~LE_WHITELIST_REMOVE_FROM_CONTROLLER;
4486 				hci_send_cmd(&hci_le_remove_device_from_white_list, entry->address_type, entry->address);
4487 				return true;
4488 			}
4489             if (entry->state & LE_WHITELIST_ADD_TO_CONTROLLER){
4490 				entry->state &= ~LE_WHITELIST_ADD_TO_CONTROLLER;
4491                 entry->state |= LE_WHITELIST_ON_CONTROLLER;
4492                 hci_send_cmd(&hci_le_add_device_to_white_list, entry->address_type, entry->address);
4493                 return true;
4494             }
4495             if ((entry->state & LE_WHITELIST_ON_CONTROLLER) == 0){
4496 				btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
4497 				btstack_memory_whitelist_entry_free(entry);
4498             }
4499         }
4500     }
4501 
4502 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
4503     // LE Resolving List Management
4504     if (resolving_list_supported) {
4505 		uint16_t i;
4506 		switch (hci_stack->le_resolving_list_state) {
4507 			case LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION:
4508 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
4509 				hci_send_cmd(&hci_le_set_address_resolution_enabled, 1);
4510 				return true;
4511 			case LE_RESOLVING_LIST_READ_SIZE:
4512 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_SEND_CLEAR;
4513 				hci_send_cmd(&hci_le_read_resolving_list_size);
4514 				return true;
4515 			case LE_RESOLVING_LIST_SEND_CLEAR:
4516 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
4517 				(void) memset(hci_stack->le_resolving_list_add_entries, 0xff,
4518 							  sizeof(hci_stack->le_resolving_list_add_entries));
4519 				(void) memset(hci_stack->le_resolving_list_remove_entries, 0,
4520 							  sizeof(hci_stack->le_resolving_list_remove_entries));
4521 				hci_send_cmd(&hci_le_clear_resolving_list);
4522 				return true;
4523 			case LE_RESOLVING_LIST_REMOVE_ENTRIES:
4524 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4525 					uint8_t offset = i >> 3;
4526 					uint8_t mask = 1 << (i & 7);
4527 					if ((hci_stack->le_resolving_list_remove_entries[offset] & mask) == 0) continue;
4528 					hci_stack->le_resolving_list_remove_entries[offset] &= ~mask;
4529 					bd_addr_t peer_identity_addreses;
4530 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4531 					sm_key_t peer_irk;
4532 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4533 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4534 
4535 #ifdef ENABLE_LE_WHITELIST_TOUCH_AFTER_RESOLVING_LIST_UPDATE
4536 					// trigger whitelist entry 'update' (work around for controller bug)
4537 					btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
4538 					while (btstack_linked_list_iterator_has_next(&lit)) {
4539 						whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&lit);
4540 						if (entry->address_type != peer_identity_addr_type) continue;
4541 						if (memcmp(entry->address, peer_identity_addreses, 6) != 0) continue;
4542 						log_info("trigger whitelist update %s", bd_addr_to_str(peer_identity_addreses));
4543 						entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER | LE_WHITELIST_ADD_TO_CONTROLLER;
4544 					}
4545 #endif
4546 
4547 					hci_send_cmd(&hci_le_remove_device_from_resolving_list, peer_identity_addr_type,
4548 								 peer_identity_addreses);
4549 					return true;
4550 				}
4551 
4552 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_ADD_ENTRIES;
4553 
4554 				/* fall through */
4555 
4556 			case LE_RESOLVING_LIST_ADD_ENTRIES:
4557 				for (i = 0; i < MAX_NUM_RESOLVING_LIST_ENTRIES && i < le_device_db_max_count(); i++) {
4558 					uint8_t offset = i >> 3;
4559 					uint8_t mask = 1 << (i & 7);
4560 					if ((hci_stack->le_resolving_list_add_entries[offset] & mask) == 0) continue;
4561 					hci_stack->le_resolving_list_add_entries[offset] &= ~mask;
4562 					bd_addr_t peer_identity_addreses;
4563 					int peer_identity_addr_type = (int) BD_ADDR_TYPE_UNKNOWN;
4564 					sm_key_t peer_irk;
4565 					le_device_db_info(i, &peer_identity_addr_type, peer_identity_addreses, peer_irk);
4566 					if (peer_identity_addr_type == BD_ADDR_TYPE_UNKNOWN) continue;
4567 					const uint8_t *local_irk = gap_get_persistent_irk();
4568 					// command uses format specifier 'P' that stores 16-byte value without flip
4569 					uint8_t local_irk_flipped[16];
4570 					uint8_t peer_irk_flipped[16];
4571 					reverse_128(local_irk, local_irk_flipped);
4572 					reverse_128(peer_irk, peer_irk_flipped);
4573 					hci_send_cmd(&hci_le_add_device_to_resolving_list, peer_identity_addr_type, peer_identity_addreses,
4574 								 peer_irk_flipped, local_irk_flipped);
4575 					return true;
4576 				}
4577 				hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4578 				break;
4579 
4580 			default:
4581 				break;
4582 		}
4583 	}
4584     hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_DONE;
4585 #endif
4586 
4587     // Phase 4: restore state
4588 
4589 #ifdef ENABLE_LE_CENTRAL
4590     // re-start scanning
4591     if ((hci_stack->le_scanning_enabled && !hci_stack->le_scanning_active)){
4592         hci_stack->le_scanning_active = true;
4593         hci_send_cmd(&hci_le_set_scan_enable, 1, 0);
4594         return true;
4595     }
4596 #endif
4597 
4598 #ifdef ENABLE_LE_CENTRAL
4599     // re-start connecting
4600     if ( (hci_stack->le_connecting_state == LE_CONNECTING_IDLE) && (hci_stack->le_connecting_request == LE_CONNECTING_WHITELIST)){
4601         bd_addr_t null_addr;
4602         memset(null_addr, 0, 6);
4603         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4604         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4605         hci_send_cmd(&hci_le_create_connection,
4606                      hci_stack->le_connection_scan_interval,    // scan interval: 60 ms
4607                      hci_stack->le_connection_scan_window,    // scan interval: 30 ms
4608                      1,         // use whitelist
4609                      0,         // peer address type
4610                      null_addr, // peer bd addr
4611                      hci_stack->le_connection_own_addr_type,   // our addr type:
4612                      hci_stack->le_connection_interval_min,    // conn interval min
4613                      hci_stack->le_connection_interval_max,    // conn interval max
4614                      hci_stack->le_connection_latency,         // conn latency
4615                      hci_stack->le_supervision_timeout,        // conn latency
4616                      hci_stack->le_minimum_ce_length,          // min ce length
4617                      hci_stack->le_maximum_ce_length           // max ce length
4618         );
4619         return true;
4620     }
4621 #endif
4622 
4623 #ifdef ENABLE_LE_PERIPHERAL
4624     // re-start advertising
4625     if (hci_stack->le_advertisements_enabled_for_current_roles && !hci_stack->le_advertisements_active){
4626         // check if advertisements should be enabled given
4627         hci_stack->le_advertisements_active = true;
4628         hci_get_own_address_for_addr_type(hci_stack->le_advertisements_own_addr_type, hci_stack->le_advertisements_own_address);
4629         hci_send_cmd(&hci_le_set_advertise_enable, 1);
4630         return true;
4631     }
4632 #endif
4633 
4634     return false;
4635 }
4636 #endif
4637 
4638 static bool hci_run_general_pending_commands(void){
4639     btstack_linked_item_t * it;
4640     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
4641         hci_connection_t * connection = (hci_connection_t *) it;
4642 
4643         switch(connection->state){
4644             case SEND_CREATE_CONNECTION:
4645                 switch(connection->address_type){
4646 #ifdef ENABLE_CLASSIC
4647                     case BD_ADDR_TYPE_ACL:
4648                         log_info("sending hci_create_connection");
4649                         hci_send_cmd(&hci_create_connection, connection->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_stack->allow_role_switch);
4650                         break;
4651 #endif
4652                     default:
4653 #ifdef ENABLE_BLE
4654 #ifdef ENABLE_LE_CENTRAL
4655                         log_info("sending hci_le_create_connection");
4656                         hci_stack->le_connection_own_addr_type =  hci_stack->le_own_addr_type;
4657                         hci_get_own_address_for_addr_type(hci_stack->le_connection_own_addr_type, hci_stack->le_connection_own_address);
4658                         hci_send_cmd(&hci_le_create_connection,
4659                                      hci_stack->le_connection_scan_interval,    // conn scan interval
4660                                      hci_stack->le_connection_scan_window,      // conn scan windows
4661                                      0,         // don't use whitelist
4662                                      connection->address_type, // peer address type
4663                                      connection->address,      // peer bd addr
4664                                      hci_stack->le_connection_own_addr_type,   // our addr type:
4665                                      hci_stack->le_connection_interval_min,    // conn interval min
4666                                      hci_stack->le_connection_interval_max,    // conn interval max
4667                                      hci_stack->le_connection_latency,         // conn latency
4668                                      hci_stack->le_supervision_timeout,        // conn latency
4669                                      hci_stack->le_minimum_ce_length,          // min ce length
4670                                      hci_stack->le_maximum_ce_length          // max ce length
4671                         );
4672                         connection->state = SENT_CREATE_CONNECTION;
4673 #endif
4674 #endif
4675                         break;
4676                 }
4677                 return true;
4678 
4679 #ifdef ENABLE_CLASSIC
4680             case RECEIVED_CONNECTION_REQUEST:
4681                 connection->role  = HCI_ROLE_SLAVE;
4682                 if (connection->address_type == BD_ADDR_TYPE_ACL){
4683                     log_info("sending hci_accept_connection_request");
4684                     connection->state = ACCEPTED_CONNECTION_REQUEST;
4685                     hci_send_cmd(&hci_accept_connection_request, connection->address, hci_stack->master_slave_policy);
4686                 }
4687                 return true;
4688 #endif
4689 
4690 #ifdef ENABLE_BLE
4691 #ifdef ENABLE_LE_CENTRAL
4692             case SEND_CANCEL_CONNECTION:
4693                 connection->state = SENT_CANCEL_CONNECTION;
4694                 hci_send_cmd(&hci_le_create_connection_cancel);
4695                 return true;
4696 #endif
4697 #endif
4698             case SEND_DISCONNECT:
4699                 connection->state = SENT_DISCONNECT;
4700                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4701                 return true;
4702 
4703             default:
4704                 break;
4705         }
4706 
4707         // no further commands if connection is about to get shut down
4708         if (connection->state == SENT_DISCONNECT) continue;
4709 
4710         if (connection->authentication_flags & AUTH_FLAG_READ_RSSI){
4711             connectionClearAuthenticationFlags(connection, AUTH_FLAG_READ_RSSI);
4712             hci_send_cmd(&hci_read_rssi, connection->con_handle);
4713             return true;
4714         }
4715 
4716 #ifdef ENABLE_CLASSIC
4717 
4718         if (connection->authentication_flags & AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT){
4719             connectionClearAuthenticationFlags(connection, AUTH_FLAG_WRITE_SUPERVISION_TIMEOUT);
4720             hci_send_cmd(&hci_write_link_supervision_timeout, connection->con_handle, hci_stack->link_supervision_timeout);
4721             return true;
4722         }
4723 
4724         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_0){
4725             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_0;
4726             hci_send_cmd(&hci_read_remote_supported_features_command, connection->con_handle);
4727             return true;
4728         }
4729 
4730         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_1){
4731             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_1;
4732             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 1);
4733             return true;
4734         }
4735 
4736         if (connection->bonding_flags & BONDING_REQUEST_REMOTE_FEATURES_PAGE_2){
4737             connection->bonding_flags &= ~BONDING_REQUEST_REMOTE_FEATURES_PAGE_2;
4738             hci_send_cmd(&hci_read_remote_extended_features_command, connection->con_handle, 2);
4739             return true;
4740         }
4741 
4742         // Handling link key request requires remote supported features
4743         if (((connection->authentication_flags & AUTH_FLAG_HANDLE_LINK_KEY_REQUEST) != 0)){
4744             log_info("responding to link key request, have link key db: %u", hci_stack->link_key_db != NULL);
4745             connectionClearAuthenticationFlags(connection, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
4746 
4747             bool have_link_key = connection->link_key_type != INVALID_LINK_KEY;
4748             bool security_level_sufficient = have_link_key && (gap_security_level_for_link_key_type(connection->link_key_type) >= connection->requested_security_level);
4749             if (have_link_key && security_level_sufficient){
4750                 hci_send_cmd(&hci_link_key_request_reply, connection->address, &connection->link_key);
4751             } else {
4752                 hci_send_cmd(&hci_link_key_request_negative_reply, connection->address);
4753             }
4754             return true;
4755         }
4756 
4757         if (connection->authentication_flags & AUTH_FLAG_DENY_PIN_CODE_REQUEST){
4758             log_info("denying to pin request");
4759             connectionClearAuthenticationFlags(connection, AUTH_FLAG_DENY_PIN_CODE_REQUEST);
4760             hci_send_cmd(&hci_pin_code_request_negative_reply, connection->address);
4761             return true;
4762         }
4763 
4764         // security assessment requires remote features
4765         if ((connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST) != 0){
4766             connectionClearAuthenticationFlags(connection, AUTH_FLAG_RECV_IO_CAPABILITIES_REQUEST);
4767             hci_ssp_assess_security_on_io_cap_request(connection);
4768             // no return here as hci_ssp_assess_security_on_io_cap_request only sets AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY or AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY
4769         }
4770 
4771         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY){
4772             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
4773             // set authentication requirements:
4774             // - MITM = ssp_authentication_requirement (USER) | requested_security_level (dynamic)
4775             // - BONDING MODE: dedicated if requested, bondable otherwise. Drop bondable if not set for remote
4776             uint8_t authreq = hci_stack->ssp_authentication_requirement & 1;
4777             if (gap_mitm_protection_required_for_security_level(connection->requested_security_level)){
4778                 authreq |= 1;
4779             }
4780             bool bonding = hci_stack->bondable;
4781             if (connection->authentication_flags & AUTH_FLAG_RECV_IO_CAPABILITIES_RESPONSE){
4782                 // if we have received IO Cap Response, we're in responder role
4783                 bool remote_bonding = connection->io_cap_response_auth_req >= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4784                 if (bonding && !remote_bonding){
4785                     log_info("Remote not bonding, dropping local flag");
4786                     bonding = false;
4787                 }
4788             }
4789             if (bonding){
4790                 if (connection->bonding_flags & BONDING_DEDICATED){
4791                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_DEDICATED_BONDING;
4792                 } else {
4793                     authreq |= SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
4794                 }
4795             }
4796             uint8_t have_oob_data = 0;
4797 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4798             if (connection->classic_oob_c_192 != NULL){
4799                     have_oob_data |= 1;
4800             }
4801             if (connection->classic_oob_c_256 != NULL){
4802                 have_oob_data |= 2;
4803             }
4804 #endif
4805             hci_send_cmd(&hci_io_capability_request_reply, &connection->address, hci_stack->ssp_io_capability, have_oob_data, authreq);
4806             return true;
4807         }
4808 
4809         if (connection->authentication_flags & AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY) {
4810             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
4811             hci_send_cmd(&hci_io_capability_request_negative_reply, &connection->address, ERROR_CODE_PAIRING_NOT_ALLOWED);
4812             return true;
4813         }
4814 
4815 #ifdef ENABLE_CLASSIC_PAIRING_OOB
4816         if (connection->authentication_flags & AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY){
4817             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_REMOTE_OOB_DATA_REPLY);
4818             const uint8_t zero[16] = { 0 };
4819             const uint8_t * r_192 = zero;
4820             const uint8_t * c_192 = zero;
4821             const uint8_t * r_256 = zero;
4822             const uint8_t * c_256 = zero;
4823             // verify P-256 OOB
4824             if ((connection->classic_oob_c_256 != NULL) && ((hci_stack->local_supported_commands[1] & 0x08u) != 0)) {
4825                 c_256 = connection->classic_oob_c_256;
4826                 if (connection->classic_oob_r_256 != NULL) {
4827                     r_256 = connection->classic_oob_r_256;
4828                 }
4829             }
4830             // verify P-192 OOB
4831             if ((connection->classic_oob_c_192 != NULL)) {
4832                 c_192 = connection->classic_oob_c_192;
4833                 if (connection->classic_oob_r_192 != NULL) {
4834                     r_192 = connection->classic_oob_r_192;
4835                 }
4836             }
4837 
4838             // assess security
4839             bool need_level_4 = hci_stack->gap_secure_connections_only_mode || (connection->requested_security_level == LEVEL_4);
4840             bool can_reach_level_4 = hci_remote_sc_enabled(connection) && (c_256 != NULL);
4841             if (need_level_4 && !can_reach_level_4){
4842                 log_info("Level 4 required, but not possible -> abort");
4843                 hci_pairing_complete(connection, ERROR_CODE_INSUFFICIENT_SECURITY);
4844                 // send oob negative reply
4845                 c_256 = NULL;
4846                 c_192 = NULL;
4847             }
4848 
4849             // Reply
4850             if (c_256 != zero) {
4851                 hci_send_cmd(&hci_remote_oob_extended_data_request_reply, &connection->address, c_192, r_192, c_256, r_256);
4852             } else if (c_192 != zero){
4853                 hci_send_cmd(&hci_remote_oob_data_request_reply, &connection->address, c_192, r_192);
4854             } else {
4855                 hci_stack->classic_oob_con_handle = connection->con_handle;
4856                 hci_send_cmd(&hci_remote_oob_data_request_negative_reply, &connection->address);
4857             }
4858             return true;
4859         }
4860 #endif
4861 
4862         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_REPLY){
4863             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_REPLY);
4864             hci_send_cmd(&hci_user_confirmation_request_reply, &connection->address);
4865             return true;
4866         }
4867 
4868         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY){
4869             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_CONFIRM_NEGATIVE_REPLY);
4870             hci_send_cmd(&hci_user_confirmation_request_negative_reply, &connection->address);
4871             return true;
4872         }
4873 
4874         if (connection->authentication_flags & AUTH_FLAG_SEND_USER_PASSKEY_REPLY){
4875             connectionClearAuthenticationFlags(connection, AUTH_FLAG_SEND_USER_PASSKEY_REPLY);
4876             hci_send_cmd(&hci_user_passkey_request_reply, &connection->address, 000000);
4877             return true;
4878         }
4879 
4880         if (connection->bonding_flags & BONDING_DISCONNECT_DEDICATED_DONE){
4881             connection->bonding_flags &= ~BONDING_DISCONNECT_DEDICATED_DONE;
4882             connection->bonding_flags |= BONDING_EMIT_COMPLETE_ON_DISCONNECT;
4883             connection->state = SENT_DISCONNECT;
4884             hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
4885             return true;
4886         }
4887 
4888         if ((connection->bonding_flags & BONDING_SEND_AUTHENTICATE_REQUEST) && ((connection->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) != 0)){
4889             connection->bonding_flags &= ~BONDING_SEND_AUTHENTICATE_REQUEST;
4890             connection->bonding_flags |= BONDING_SENT_AUTHENTICATE_REQUEST;
4891             hci_send_cmd(&hci_authentication_requested, connection->con_handle);
4892             return true;
4893         }
4894 
4895         if (connection->bonding_flags & BONDING_SEND_ENCRYPTION_REQUEST){
4896             connection->bonding_flags &= ~BONDING_SEND_ENCRYPTION_REQUEST;
4897             hci_send_cmd(&hci_set_connection_encryption, connection->con_handle, 1);
4898             return true;
4899         }
4900         if (connection->bonding_flags & BONDING_SEND_READ_ENCRYPTION_KEY_SIZE){
4901             connection->bonding_flags &= ~BONDING_SEND_READ_ENCRYPTION_KEY_SIZE;
4902             hci_send_cmd(&hci_read_encryption_key_size, connection->con_handle, 1);
4903             return true;
4904         }
4905 #endif
4906 
4907         if (connection->bonding_flags & BONDING_DISCONNECT_SECURITY_BLOCK){
4908             connection->bonding_flags &= ~BONDING_DISCONNECT_SECURITY_BLOCK;
4909 #ifdef ENABLE_CLASSIC
4910             hci_pairing_complete(connection, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_SECURITY_REASONS);
4911 #endif
4912             if (connection->state != SENT_DISCONNECT){
4913                 connection->state = SENT_DISCONNECT;
4914                 hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_AUTHENTICATION_FAILURE);
4915                 return true;
4916             }
4917         }
4918 
4919 #ifdef ENABLE_CLASSIC
4920         uint16_t sniff_min_interval;
4921         switch (connection->sniff_min_interval){
4922             case 0:
4923                 break;
4924             case 0xffff:
4925                 connection->sniff_min_interval = 0;
4926                 hci_send_cmd(&hci_exit_sniff_mode, connection->con_handle);
4927                 return true;
4928             default:
4929                 sniff_min_interval = connection->sniff_min_interval;
4930                 connection->sniff_min_interval = 0;
4931                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
4932                 return true;
4933         }
4934 
4935         if (connection->sniff_subrating_max_latency != 0xffff){
4936             uint16_t max_latency = connection->sniff_subrating_max_latency;
4937             connection->sniff_subrating_max_latency = 0;
4938             hci_send_cmd(&hci_sniff_subrating, connection->con_handle, max_latency, connection->sniff_subrating_min_remote_timeout, connection->sniff_subrating_min_local_timeout);
4939             return true;
4940         }
4941 
4942         if (connection->qos_service_type != HCI_SERVICE_TYPE_INVALID){
4943             uint8_t service_type = (uint8_t) connection->qos_service_type;
4944             connection->qos_service_type = HCI_SERVICE_TYPE_INVALID;
4945             hci_send_cmd(&hci_qos_setup, connection->con_handle, 0, service_type, connection->qos_token_rate, connection->qos_peak_bandwidth, connection->qos_latency, connection->qos_delay_variation);
4946             return true;
4947         }
4948 
4949         if (connection->request_role != HCI_ROLE_INVALID){
4950             hci_role_t role = connection->request_role;
4951             connection->request_role = HCI_ROLE_INVALID;
4952             hci_send_cmd(&hci_switch_role_command, connection->address, role);
4953             return true;
4954         }
4955 #endif
4956 
4957 #ifdef ENABLE_BLE
4958         switch (connection->le_con_parameter_update_state){
4959             // response to L2CAP CON PARAMETER UPDATE REQUEST
4960             case CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS:
4961                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4962                 hci_send_cmd(&hci_le_connection_update, connection->con_handle, connection->le_conn_interval_min,
4963                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4964                              0x0000, 0xffff);
4965                 return true;
4966             case CON_PARAMETER_UPDATE_REPLY:
4967                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4968                 hci_send_cmd(&hci_le_remote_connection_parameter_request_reply, connection->con_handle, connection->le_conn_interval_min,
4969                              connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout,
4970                              0x0000, 0xffff);
4971                 return true;
4972             case CON_PARAMETER_UPDATE_NEGATIVE_REPLY:
4973                 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE;
4974                 hci_send_cmd(&hci_le_remote_connection_parameter_request_negative_reply, ERROR_CODE_UNSUPPORTED_LMP_PARAMETER_VALUE_UNSUPPORTED_LL_PARAMETER_VALUE);
4975                 return true;
4976             default:
4977                 break;
4978         }
4979         if (connection->le_phy_update_all_phys != 0xffu){
4980             uint8_t all_phys = connection->le_phy_update_all_phys;
4981             connection->le_phy_update_all_phys = 0xff;
4982             hci_send_cmd(&hci_le_set_phy, connection->con_handle, all_phys, connection->le_phy_update_tx_phys, connection->le_phy_update_rx_phys, connection->le_phy_update_phy_options);
4983             return true;
4984         }
4985 #endif
4986     }
4987     return false;
4988 }
4989 
4990 static void hci_run(void){
4991 
4992     bool done;
4993 
4994     // send continuation fragments first, as they block the prepared packet buffer
4995     done = hci_run_acl_fragments();
4996     if (done) return;
4997 
4998 #ifdef ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
4999     // send host num completed packets next as they don't require num_cmd_packets > 0
5000     if (!hci_can_send_comand_packet_transport()) return;
5001     if (hci_stack->host_completed_packets){
5002         hci_host_num_completed_packets();
5003         return;
5004     }
5005 #endif
5006 
5007     if (!hci_can_send_command_packet_now()) return;
5008 
5009     // global/non-connection oriented commands
5010 
5011 
5012 #ifdef ENABLE_CLASSIC
5013     // general gap classic
5014     done = hci_run_general_gap_classic();
5015     if (done) return;
5016 #endif
5017 
5018 #ifdef ENABLE_BLE
5019     // general gap le
5020     done = hci_run_general_gap_le();
5021     if (done) return;
5022 #endif
5023 
5024     // send pending HCI commands
5025     done = hci_run_general_pending_commands();
5026     if (done) return;
5027 
5028     // stack state sub statemachines
5029     hci_connection_t * connection;
5030     switch (hci_stack->state){
5031         case HCI_STATE_INITIALIZING:
5032             hci_initializing_run();
5033             break;
5034 
5035         case HCI_STATE_HALTING:
5036 
5037             log_info("HCI_STATE_HALTING, substate %x\n", hci_stack->substate);
5038             switch (hci_stack->substate){
5039                 case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
5040                 case HCI_HALTING_DISCONNECT_ALL_TIMER:
5041 
5042 #ifdef ENABLE_BLE
5043 #ifdef ENABLE_LE_CENTRAL
5044                     // free whitelist entries
5045                     {
5046                         btstack_linked_list_iterator_t lit;
5047                         btstack_linked_list_iterator_init(&lit, &hci_stack->le_whitelist);
5048                         while (btstack_linked_list_iterator_has_next(&lit)){
5049                             whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&lit);
5050                             btstack_linked_list_remove(&hci_stack->le_whitelist, (btstack_linked_item_t *) entry);
5051                             btstack_memory_whitelist_entry_free(entry);
5052                         }
5053                     }
5054 #endif
5055 #endif
5056                     // close all open connections
5057                     connection =  (hci_connection_t *) hci_stack->connections;
5058                     if (connection){
5059                         hci_con_handle_t con_handle = (uint16_t) connection->con_handle;
5060                         if (!hci_can_send_command_packet_now()) return;
5061 
5062                         // check state
5063                         if (connection->state == SENT_DISCONNECT) return;
5064                         connection->state = SENT_DISCONNECT;
5065 
5066                         log_info("HCI_STATE_HALTING, connection %p, handle %u", connection, con_handle);
5067 
5068                         // cancel all l2cap connections right away instead of waiting for disconnection complete event ...
5069                         hci_emit_disconnection_complete(con_handle, 0x16); // terminated by local host
5070 
5071                         // ... which would be ignored anyway as we shutdown (free) the connection now
5072                         hci_shutdown_connection(connection);
5073 
5074                         // finally, send the disconnect command
5075                         hci_send_cmd(&hci_disconnect, con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5076                         return;
5077                     }
5078 
5079                     if (hci_stack->substate == HCI_HALTING_DISCONNECT_ALL_TIMER){
5080                         // no connections left, wait a bit to assert that btstack_cyrpto isn't waiting for an HCI event
5081                         log_info("HCI_STATE_HALTING: wait 50 ms");
5082                         hci_stack->substate = HCI_HALTING_W4_TIMER;
5083                         btstack_run_loop_set_timer(&hci_stack->timeout, 50);
5084                         btstack_run_loop_set_timer_handler(&hci_stack->timeout, hci_halting_timeout_handler);
5085                         btstack_run_loop_add_timer(&hci_stack->timeout);
5086                         break;
5087                     }
5088 
5089                     /* fall through */
5090 
5091                 case HCI_HALTING_CLOSE:
5092                     log_info("HCI_STATE_HALTING, calling off");
5093 
5094                     // switch mode
5095                     hci_power_control_off();
5096 
5097                     log_info("HCI_STATE_HALTING, emitting state");
5098                     hci_emit_state();
5099                     log_info("HCI_STATE_HALTING, done");
5100                     break;
5101 
5102                 case HCI_HALTING_W4_TIMER:
5103                     // keep waiting
5104 
5105                     break;
5106                 default:
5107                     break;
5108             }
5109 
5110             break;
5111 
5112         case HCI_STATE_FALLING_ASLEEP:
5113             switch(hci_stack->substate) {
5114                 case HCI_FALLING_ASLEEP_DISCONNECT:
5115                     log_info("HCI_STATE_FALLING_ASLEEP");
5116                     // close all open connections
5117                     connection =  (hci_connection_t *) hci_stack->connections;
5118                     if (connection){
5119 
5120                         // send disconnect
5121                         if (!hci_can_send_command_packet_now()) return;
5122 
5123                         log_info("HCI_STATE_FALLING_ASLEEP, connection %p, handle %u", connection, (uint16_t)connection->con_handle);
5124                         hci_send_cmd(&hci_disconnect, connection->con_handle, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION);
5125 
5126                         // send disconnected event right away - causes higher layer connections to get closed, too.
5127                         hci_shutdown_connection(connection);
5128                         return;
5129                     }
5130 
5131                     if (hci_classic_supported()){
5132                         // disable page and inquiry scan
5133                         if (!hci_can_send_command_packet_now()) return;
5134 
5135                         log_info("HCI_STATE_HALTING, disabling inq scans");
5136                         hci_send_cmd(&hci_write_scan_enable, hci_stack->connectable << 1); // drop inquiry scan but keep page scan
5137 
5138                         // continue in next sub state
5139                         hci_stack->substate = HCI_FALLING_ASLEEP_W4_WRITE_SCAN_ENABLE;
5140                         break;
5141                     }
5142 
5143                     /* fall through */
5144 
5145                 case HCI_FALLING_ASLEEP_COMPLETE:
5146                     log_info("HCI_STATE_HALTING, calling sleep");
5147                     // switch mode
5148                     hci_power_control_sleep();  // changes hci_stack->state to SLEEP
5149                     hci_emit_state();
5150                     break;
5151 
5152                 default:
5153                     break;
5154             }
5155             break;
5156 
5157         default:
5158             break;
5159     }
5160 }
5161 
5162 uint8_t hci_send_cmd_packet(uint8_t *packet, int size){
5163     // house-keeping
5164 
5165 #ifdef ENABLE_CLASSIC
5166     bd_addr_t addr;
5167     hci_connection_t * conn;
5168 #endif
5169 #ifdef ENABLE_LE_CENTRAL
5170     uint8_t initiator_filter_policy;
5171 #endif
5172 
5173     uint16_t opcode = little_endian_read_16(packet, 0);
5174     switch (opcode) {
5175         case HCI_OPCODE_HCI_WRITE_LOOPBACK_MODE:
5176             hci_stack->loopback_mode = packet[3];
5177             break;
5178 
5179 #ifdef ENABLE_CLASSIC
5180         case HCI_OPCODE_HCI_CREATE_CONNECTION:
5181             reverse_bd_addr(&packet[3], addr);
5182             log_info("Create_connection to %s", bd_addr_to_str(addr));
5183 
5184             // CVE-2020-26555: reject outgoing connection to device with same BD ADDR
5185             if (memcmp(hci_stack->local_bd_addr, addr, 6) == 0) {
5186                 hci_emit_connection_complete(addr, 0, ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR);
5187                 return ERROR_CODE_CONNECTION_REJECTED_DUE_TO_UNACCEPTABLE_BD_ADDR;
5188             }
5189 
5190             conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5191             if (!conn) {
5192                 conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
5193                 if (!conn) {
5194                     // notify client that alloc failed
5195                     hci_emit_connection_complete(addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5196                     return BTSTACK_MEMORY_ALLOC_FAILED; // packet not sent to controller
5197                 }
5198                 conn->state = SEND_CREATE_CONNECTION;
5199                 conn->role  = HCI_ROLE_MASTER;
5200             }
5201 
5202             conn->con_handle = HCI_CON_HANDLE_INVALID;
5203             conn->role = HCI_ROLE_INVALID;
5204 
5205             log_info("conn state %u", conn->state);
5206             // TODO: L2CAP should not send create connection command, instead a (new) gap function should be used
5207             switch (conn->state) {
5208                 // if connection active exists
5209                 case OPEN:
5210                     // and OPEN, emit connection complete command
5211                     hci_emit_connection_complete(addr, conn->con_handle, ERROR_CODE_SUCCESS);
5212                     // packet not sent to controller
5213                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5214                 case RECEIVED_DISCONNECTION_COMPLETE:
5215                     // create connection triggered in disconnect complete event, let's do it now
5216                     break;
5217                 case SEND_CREATE_CONNECTION:
5218                     // connection created by hci, e.g. dedicated bonding, but not executed yet, let's do it now
5219                     break;
5220                 default:
5221                     // otherwise, just ignore as it is already in the open process
5222                     // packet not sent to controller
5223                     return ERROR_CODE_ACL_CONNECTION_ALREADY_EXISTS;
5224             }
5225             conn->state = SENT_CREATE_CONNECTION;
5226 
5227             // track outgoing connection
5228             hci_stack->outgoing_addr_type = BD_ADDR_TYPE_ACL;
5229             (void) memcpy(hci_stack->outgoing_addr, addr, 6);
5230             break;
5231         case HCI_OPCODE_HCI_DELETE_STORED_LINK_KEY:
5232             if (hci_stack->link_key_db) {
5233                 reverse_bd_addr(&packet[3], addr);
5234                 hci_stack->link_key_db->delete_link_key(addr);
5235             }
5236             break;
5237 
5238 #if defined (ENABLE_SCO_OVER_HCI) || defined (HAVE_SCO_TRANSPORT)
5239         case HCI_OPCODE_HCI_SETUP_SYNCHRONOUS_CONNECTION:
5240             // setup_synchronous_connection? Voice setting at offset 22
5241             // TODO: compare to current setting if sco connection already active
5242             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 15);
5243             break;
5244         case HCI_OPCODE_HCI_ACCEPT_SYNCHRONOUS_CONNECTION:
5245             // accept_synchronus_connection? Voice setting at offset 18
5246             // TODO: compare to current setting if sco connection already active
5247             hci_stack->sco_voice_setting_active = little_endian_read_16(packet, 19);
5248             break;
5249 #endif
5250 #endif
5251 
5252 #ifdef ENABLE_BLE
5253         case HCI_OPCODE_HCI_LE_SET_RANDOM_ADDRESS:
5254             hci_stack->le_random_address_set = 1;
5255             reverse_bd_addr(&packet[3], hci_stack->le_random_address);
5256             break;
5257 #ifdef ENABLE_LE_PERIPHERAL
5258         case HCI_OPCODE_HCI_LE_SET_ADVERTISE_ENABLE:
5259             hci_stack->le_advertisements_active = packet[3] != 0;
5260             break;
5261 #endif
5262 #ifdef ENABLE_LE_CENTRAL
5263         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION:
5264             // white list used?
5265             initiator_filter_policy = packet[7];
5266             switch (initiator_filter_policy) {
5267                 case 0:
5268                     // whitelist not used
5269                     hci_stack->le_connecting_state = LE_CONNECTING_DIRECT;
5270                     break;
5271                 case 1:
5272                     hci_stack->le_connecting_state = LE_CONNECTING_WHITELIST;
5273                     break;
5274                 default:
5275                     log_error("Invalid initiator_filter_policy in LE Create Connection %u", initiator_filter_policy);
5276                     break;
5277             }
5278             // track outgoing connection
5279             hci_stack->outgoing_addr_type = (bd_addr_type_t) packet[8]; // peer addres type
5280             reverse_bd_addr( &packet[9], hci_stack->outgoing_addr); // peer address
5281             break;
5282         case HCI_OPCODE_HCI_LE_CREATE_CONNECTION_CANCEL:
5283             hci_stack->le_connecting_state = LE_CONNECTING_CANCEL;
5284             break;
5285 #endif
5286 #endif
5287         default:
5288             break;
5289     }
5290 
5291     hci_stack->num_cmd_packets--;
5292 
5293     hci_dump_packet(HCI_COMMAND_DATA_PACKET, 0, packet, size);
5294     int err = hci_stack->hci_transport->send_packet(HCI_COMMAND_DATA_PACKET, packet, size);
5295     if (err != 0){
5296         return ERROR_CODE_HARDWARE_FAILURE;
5297     }
5298     return ERROR_CODE_SUCCESS;
5299 }
5300 
5301 // disconnect because of security block
5302 void hci_disconnect_security_block(hci_con_handle_t con_handle){
5303     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5304     if (!connection) return;
5305     connection->bonding_flags |= BONDING_DISCONNECT_SECURITY_BLOCK;
5306 }
5307 
5308 
5309 // Configure Secure Simple Pairing
5310 
5311 #ifdef ENABLE_CLASSIC
5312 
5313 // enable will enable SSP during init
5314 void gap_ssp_set_enable(int enable){
5315     hci_stack->ssp_enable = enable;
5316 }
5317 
5318 static int hci_local_ssp_activated(void){
5319     return gap_ssp_supported() && hci_stack->ssp_enable;
5320 }
5321 
5322 // if set, BTstack will respond to io capability request using authentication requirement
5323 void gap_ssp_set_io_capability(int io_capability){
5324     hci_stack->ssp_io_capability = io_capability;
5325 }
5326 void gap_ssp_set_authentication_requirement(int authentication_requirement){
5327     hci_stack->ssp_authentication_requirement = authentication_requirement;
5328 }
5329 
5330 // if set, BTstack will confirm a numberic comparion and enter '000000' if requested
5331 void gap_ssp_set_auto_accept(int auto_accept){
5332     hci_stack->ssp_auto_accept = auto_accept;
5333 }
5334 
5335 void gap_secure_connections_enable(bool enable){
5336     hci_stack->secure_connections_enable = enable;
5337 }
5338 
5339 #endif
5340 
5341 // va_list part of hci_send_cmd
5342 uint8_t hci_send_cmd_va_arg(const hci_cmd_t * cmd, va_list argptr){
5343     if (!hci_can_send_command_packet_now()){
5344         log_error("hci_send_cmd called but cannot send packet now");
5345         return ERROR_CODE_COMMAND_DISALLOWED;
5346     }
5347 
5348     // for HCI INITIALIZATION
5349     // log_info("hci_send_cmd: opcode %04x", cmd->opcode);
5350     hci_stack->last_cmd_opcode = cmd->opcode;
5351 
5352     hci_reserve_packet_buffer();
5353     uint8_t * packet = hci_stack->hci_packet_buffer;
5354     uint16_t size = hci_cmd_create_from_template(packet, cmd, argptr);
5355     uint8_t status = hci_send_cmd_packet(packet, size);
5356 
5357     // release packet buffer on error or for synchronous transport implementations
5358     if ((status != ERROR_CODE_SUCCESS) || hci_transport_synchronous()){
5359         hci_release_packet_buffer();
5360         hci_emit_transport_packet_sent();
5361     }
5362 
5363     return status;
5364 }
5365 
5366 /**
5367  * pre: numcmds >= 0 - it's allowed to send a command to the controller
5368  */
5369 uint8_t hci_send_cmd(const hci_cmd_t * cmd, ...){
5370     va_list argptr;
5371     va_start(argptr, cmd);
5372     uint8_t status = hci_send_cmd_va_arg(cmd, argptr);
5373     va_end(argptr);
5374     return status;
5375 }
5376 
5377 // Create various non-HCI events.
5378 // TODO: generalize, use table similar to hci_create_command
5379 
5380 static void hci_emit_event(uint8_t * event, uint16_t size, int dump){
5381     // dump packet
5382     if (dump) {
5383         hci_dump_packet( HCI_EVENT_PACKET, 0, event, size);
5384     }
5385 
5386     // dispatch to all event handlers
5387     btstack_linked_list_iterator_t it;
5388     btstack_linked_list_iterator_init(&it, &hci_stack->event_handlers);
5389     while (btstack_linked_list_iterator_has_next(&it)){
5390         btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it);
5391         entry->callback(HCI_EVENT_PACKET, 0, event, size);
5392     }
5393 }
5394 
5395 static void hci_emit_acl_packet(uint8_t * packet, uint16_t size){
5396     if (!hci_stack->acl_packet_handler) return;
5397     hci_stack->acl_packet_handler(HCI_ACL_DATA_PACKET, 0, packet, size);
5398 }
5399 
5400 #ifdef ENABLE_CLASSIC
5401 static void hci_notify_if_sco_can_send_now(void){
5402     // notify SCO sender if waiting
5403     if (!hci_stack->sco_waiting_for_can_send_now) return;
5404     if (hci_can_send_sco_packet_now()){
5405         hci_stack->sco_waiting_for_can_send_now = 0;
5406         uint8_t event[2] = { HCI_EVENT_SCO_CAN_SEND_NOW, 0 };
5407         hci_dump_packet(HCI_EVENT_PACKET, 1, event, sizeof(event));
5408         hci_stack->sco_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
5409     }
5410 }
5411 
5412 // parsing end emitting has been merged to reduce code size
5413 static void gap_inquiry_explode(uint8_t *packet, uint16_t size) {
5414     uint8_t event[28+GAP_INQUIRY_MAX_NAME_LEN];
5415 
5416     uint8_t * eir_data;
5417     ad_context_t context;
5418     const uint8_t * name;
5419     uint8_t         name_len;
5420 
5421     if (size < 3) return;
5422 
5423     int event_type = hci_event_packet_get_type(packet);
5424     int num_reserved_fields = (event_type == HCI_EVENT_INQUIRY_RESULT) ? 2 : 1;    // 2 for old event, 1 otherwise
5425     int num_responses       = hci_event_inquiry_result_get_num_responses(packet);
5426 
5427     switch (event_type){
5428         case HCI_EVENT_INQUIRY_RESULT:
5429         case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5430             if (size != (3 + (num_responses * 14))) return;
5431             break;
5432         case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5433             if (size != 257) return;
5434             if (num_responses != 1) return;
5435             break;
5436         default:
5437             return;
5438     }
5439 
5440     // event[1] is set at the end
5441     int i;
5442     for (i=0; i<num_responses;i++){
5443         memset(event, 0, sizeof(event));
5444         event[0] = GAP_EVENT_INQUIRY_RESULT;
5445         uint8_t event_size = 27;    // if name is not set by EIR
5446 
5447         (void)memcpy(&event[2], &packet[3 + (i * 6)], 6); // bd_addr
5448         event[8] =          packet[3 + (num_responses*(6))                         + (i*1)];     // page_scan_repetition_mode
5449         (void)memcpy(&event[9],
5450                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields)) + (i * 3)],
5451                      3); // class of device
5452         (void)memcpy(&event[12],
5453                      &packet[3 + (num_responses * (6 + 1 + num_reserved_fields + 3)) + (i * 2)],
5454                      2); // clock offset
5455 
5456         switch (event_type){
5457             case HCI_EVENT_INQUIRY_RESULT:
5458                 // 14,15,16,17 = 0, size 18
5459                 break;
5460             case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI:
5461                 event[14] = 1;
5462                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5463                 // 16,17 = 0, size 18
5464                 break;
5465             case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE:
5466                 event[14] = 1;
5467                 event[15] = packet [3 + (num_responses*(6+1+num_reserved_fields+3+2)) + (i*1)]; // rssi
5468                 // EIR packets only contain a single inquiry response
5469                 eir_data = &packet[3 + (6+1+num_reserved_fields+3+2+1)];
5470                 name = NULL;
5471                 // Iterate over EIR data
5472                 for (ad_iterator_init(&context, EXTENDED_INQUIRY_RESPONSE_DATA_LEN, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
5473                     uint8_t data_type    = ad_iterator_get_data_type(&context);
5474                     uint8_t data_size    = ad_iterator_get_data_len(&context);
5475                     const uint8_t * data = ad_iterator_get_data(&context);
5476                     // Prefer Complete Local Name over Shortened Local Name
5477                     switch (data_type){
5478                         case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME:
5479                             if (name) continue;
5480                             /* fall through */
5481                         case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME:
5482                             name = data;
5483                             name_len = data_size;
5484                             break;
5485                         case BLUETOOTH_DATA_TYPE_DEVICE_ID:
5486                             if (data_size != 8) break;
5487                             event[16] = 1;
5488                             memcpy(&event[17], data, 8);
5489                             break;
5490                         default:
5491                             break;
5492                     }
5493                 }
5494                 if (name){
5495                     event[25] = 1;
5496                     // truncate name if needed
5497                     int len = btstack_min(name_len, GAP_INQUIRY_MAX_NAME_LEN);
5498                     event[26] = len;
5499                     (void)memcpy(&event[27], name, len);
5500                     event_size += len;
5501                 }
5502                 break;
5503             default:
5504                 return;
5505         }
5506         event[1] = event_size - 2;
5507         hci_emit_event(event, event_size, 1);
5508     }
5509 }
5510 #endif
5511 
5512 void hci_emit_state(void){
5513     log_info("BTSTACK_EVENT_STATE %u", hci_stack->state);
5514     uint8_t event[3];
5515     event[0] = BTSTACK_EVENT_STATE;
5516     event[1] = sizeof(event) - 2u;
5517     event[2] = hci_stack->state;
5518     hci_emit_event(event, sizeof(event), 1);
5519 }
5520 
5521 #ifdef ENABLE_CLASSIC
5522 static void hci_emit_connection_complete(bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5523     uint8_t event[13];
5524     event[0] = HCI_EVENT_CONNECTION_COMPLETE;
5525     event[1] = sizeof(event) - 2;
5526     event[2] = status;
5527     little_endian_store_16(event, 3, con_handle);
5528     reverse_bd_addr(address, &event[5]);
5529     event[11] = 1; // ACL connection
5530     event[12] = 0; // encryption disabled
5531     hci_emit_event(event, sizeof(event), 1);
5532 }
5533 static void hci_emit_l2cap_check_timeout(hci_connection_t *conn){
5534     if (disable_l2cap_timeouts) return;
5535     log_info("L2CAP_EVENT_TIMEOUT_CHECK");
5536     uint8_t event[4];
5537     event[0] = L2CAP_EVENT_TIMEOUT_CHECK;
5538     event[1] = sizeof(event) - 2;
5539     little_endian_store_16(event, 2, conn->con_handle);
5540     hci_emit_event(event, sizeof(event), 1);
5541 }
5542 #endif
5543 
5544 #ifdef ENABLE_BLE
5545 #ifdef ENABLE_LE_CENTRAL
5546 static void hci_emit_le_connection_complete(uint8_t address_type, const bd_addr_t address, hci_con_handle_t con_handle, uint8_t status){
5547     uint8_t event[21];
5548     event[0] = HCI_EVENT_LE_META;
5549     event[1] = sizeof(event) - 2u;
5550     event[2] = HCI_SUBEVENT_LE_CONNECTION_COMPLETE;
5551     event[3] = status;
5552     little_endian_store_16(event, 4, con_handle);
5553     event[6] = 0; // TODO: role
5554     event[7] = address_type;
5555     reverse_bd_addr(address, &event[8]);
5556     little_endian_store_16(event, 14, 0); // interval
5557     little_endian_store_16(event, 16, 0); // latency
5558     little_endian_store_16(event, 18, 0); // supervision timeout
5559     event[20] = 0; // master clock accuracy
5560     hci_emit_event(event, sizeof(event), 1);
5561 }
5562 #endif
5563 #endif
5564 
5565 static void hci_emit_transport_packet_sent(void){
5566     // notify upper stack that it might be possible to send again
5567     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
5568     hci_emit_event(&event[0], sizeof(event), 0);  // don't dump
5569 }
5570 
5571 static void hci_emit_disconnection_complete(hci_con_handle_t con_handle, uint8_t reason){
5572     uint8_t event[6];
5573     event[0] = HCI_EVENT_DISCONNECTION_COMPLETE;
5574     event[1] = sizeof(event) - 2u;
5575     event[2] = 0; // status = OK
5576     little_endian_store_16(event, 3, con_handle);
5577     event[5] = reason;
5578     hci_emit_event(event, sizeof(event), 1);
5579 }
5580 
5581 static void hci_emit_nr_connections_changed(void){
5582     log_info("BTSTACK_EVENT_NR_CONNECTIONS_CHANGED %u", nr_hci_connections());
5583     uint8_t event[3];
5584     event[0] = BTSTACK_EVENT_NR_CONNECTIONS_CHANGED;
5585     event[1] = sizeof(event) - 2u;
5586     event[2] = nr_hci_connections();
5587     hci_emit_event(event, sizeof(event), 1);
5588 }
5589 
5590 static void hci_emit_hci_open_failed(void){
5591     log_info("BTSTACK_EVENT_POWERON_FAILED");
5592     uint8_t event[2];
5593     event[0] = BTSTACK_EVENT_POWERON_FAILED;
5594     event[1] = sizeof(event) - 2u;
5595     hci_emit_event(event, sizeof(event), 1);
5596 }
5597 
5598 static void hci_emit_dedicated_bonding_result(bd_addr_t address, uint8_t status){
5599     log_info("hci_emit_dedicated_bonding_result %u ", status);
5600     uint8_t event[9];
5601     int pos = 0;
5602     event[pos++] = GAP_EVENT_DEDICATED_BONDING_COMPLETED;
5603     event[pos++] = sizeof(event) - 2u;
5604     event[pos++] = status;
5605     reverse_bd_addr(address, &event[pos]);
5606     hci_emit_event(event, sizeof(event), 1);
5607 }
5608 
5609 
5610 #ifdef ENABLE_CLASSIC
5611 
5612 static void hci_emit_security_level(hci_con_handle_t con_handle, gap_security_level_t level){
5613     log_info("hci_emit_security_level %u for handle %x", level, con_handle);
5614     uint8_t event[5];
5615     int pos = 0;
5616     event[pos++] = GAP_EVENT_SECURITY_LEVEL;
5617     event[pos++] = sizeof(event) - 2;
5618     little_endian_store_16(event, 2, con_handle);
5619     pos += 2;
5620     event[pos++] = level;
5621     hci_emit_event(event, sizeof(event), 1);
5622 }
5623 
5624 static gap_security_level_t gap_security_level_for_connection(hci_connection_t * connection){
5625     if (!connection) return LEVEL_0;
5626     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED) == 0) return LEVEL_0;
5627     // BIAS: we only consider Authenticated if the connection is already encrypted, which requires that both sides have link key
5628     if ((connection->authentication_flags & AUTH_FLAG_CONNECTION_AUTHENTICATED) == 0) return LEVEL_0;
5629     if (connection->encryption_key_size < hci_stack->gap_required_encyrption_key_size) return LEVEL_0;
5630     gap_security_level_t security_level = gap_security_level_for_link_key_type(connection->link_key_type);
5631     // LEVEL 4 always requires 128 bit encrytion key size
5632     if ((security_level == LEVEL_4) && (connection->encryption_key_size < 16)){
5633         security_level = LEVEL_3;
5634     }
5635     return security_level;
5636 }
5637 
5638 static void hci_emit_discoverable_enabled(uint8_t enabled){
5639     log_info("BTSTACK_EVENT_DISCOVERABLE_ENABLED %u", enabled);
5640     uint8_t event[3];
5641     event[0] = BTSTACK_EVENT_DISCOVERABLE_ENABLED;
5642     event[1] = sizeof(event) - 2;
5643     event[2] = enabled;
5644     hci_emit_event(event, sizeof(event), 1);
5645 }
5646 
5647 // query if remote side supports eSCO
5648 bool hci_remote_esco_supported(hci_con_handle_t con_handle){
5649     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5650     if (!connection) return false;
5651     return (connection->remote_supported_features[0] & 1) != 0;
5652 }
5653 
5654 static bool hci_ssp_supported(hci_connection_t * connection){
5655     const uint8_t mask = BONDING_REMOTE_SUPPORTS_SSP_CONTROLLER | BONDING_REMOTE_SUPPORTS_SSP_HOST;
5656     return (connection->bonding_flags & mask) == mask;
5657 }
5658 
5659 // query if remote side supports SSP
5660 bool hci_remote_ssp_supported(hci_con_handle_t con_handle){
5661     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5662     if (!connection) return false;
5663     return hci_ssp_supported(connection) ? 1 : 0;
5664 }
5665 
5666 bool gap_ssp_supported_on_both_sides(hci_con_handle_t handle){
5667     return hci_local_ssp_activated() && hci_remote_ssp_supported(handle);
5668 }
5669 
5670 // GAP API
5671 /**
5672  * @bbrief enable/disable bonding. default is enabled
5673  * @praram enabled
5674  */
5675 void gap_set_bondable_mode(int enable){
5676     hci_stack->bondable = enable ? 1 : 0;
5677 }
5678 /**
5679  * @brief Get bondable mode.
5680  * @return 1 if bondable
5681  */
5682 int gap_get_bondable_mode(void){
5683     return hci_stack->bondable;
5684 }
5685 
5686 /**
5687  * @brief map link keys to security levels
5688  */
5689 gap_security_level_t gap_security_level_for_link_key_type(link_key_type_t link_key_type){
5690     switch (link_key_type){
5691         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5692             return LEVEL_4;
5693         case COMBINATION_KEY:
5694         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5695             return LEVEL_3;
5696         default:
5697             return LEVEL_2;
5698     }
5699 }
5700 
5701 /**
5702  * @brief map link keys to secure connection yes/no
5703  */
5704 int gap_secure_connection_for_link_key_type(link_key_type_t link_key_type){
5705     switch (link_key_type){
5706         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5707         case UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5708             return 1;
5709         default:
5710             return 0;
5711     }
5712 }
5713 
5714 /**
5715  * @brief map link keys to authenticated
5716  */
5717 int gap_authenticated_for_link_key_type(link_key_type_t link_key_type){
5718     switch (link_key_type){
5719         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256:
5720         case AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P192:
5721             return 1;
5722         default:
5723             return 0;
5724     }
5725 }
5726 
5727 int gap_mitm_protection_required_for_security_level(gap_security_level_t level){
5728     log_info("gap_mitm_protection_required_for_security_level %u", level);
5729     return level > LEVEL_2;
5730 }
5731 
5732 /**
5733  * @brief get current security level
5734  */
5735 gap_security_level_t gap_security_level(hci_con_handle_t con_handle){
5736     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5737     if (!connection) return LEVEL_0;
5738     return gap_security_level_for_connection(connection);
5739 }
5740 
5741 /**
5742  * @brief request connection to device to
5743  * @result GAP_AUTHENTICATION_RESULT
5744  */
5745 void gap_request_security_level(hci_con_handle_t con_handle, gap_security_level_t requested_level){
5746     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5747     if (!connection){
5748         hci_emit_security_level(con_handle, LEVEL_0);
5749         return;
5750     }
5751 
5752     btstack_assert(hci_is_le_connection(connection) == false);
5753 
5754     // Core Spec 5.2, GAP 5.2.2: "When in Secure Connections Only mode, all services (except those allowed to have Security Mode 4, Level 0)
5755     // available on the BR/EDR physical transport require Security Mode 4, Level 4 "
5756     if (hci_stack->gap_secure_connections_only_mode && (requested_level != LEVEL_0)){
5757         requested_level = LEVEL_4;
5758     }
5759 
5760     gap_security_level_t current_level = gap_security_level(con_handle);
5761     log_info("gap_request_security_level requested level %u, planned level %u, current level %u",
5762         requested_level, connection->requested_security_level, current_level);
5763 
5764     // authentication active if authentication request was sent or planned level > 0
5765     bool authentication_active = ((connection->bonding_flags & BONDING_SENT_AUTHENTICATE_REQUEST) != 0) || (connection->requested_security_level > LEVEL_0);
5766     if (authentication_active){
5767         // authentication already active
5768         if (connection->requested_security_level < requested_level){
5769             // increase requested level as new level is higher
5770             // TODO: handle re-authentication when done
5771             connection->requested_security_level = requested_level;
5772         }
5773     } else {
5774         // no request active, notify if security sufficient
5775         if (requested_level <= current_level){
5776             hci_emit_security_level(con_handle, current_level);
5777             return;
5778         }
5779 
5780         // store request
5781         connection->requested_security_level = requested_level;
5782 
5783         // start to authenticate connection
5784         connection->bonding_flags |= BONDING_SEND_AUTHENTICATE_REQUEST;
5785         hci_run();
5786     }
5787 }
5788 
5789 /**
5790  * @brief start dedicated bonding with device. disconnect after bonding
5791  * @param device
5792  * @param request MITM protection
5793  * @result GAP_DEDICATED_BONDING_COMPLETE
5794  */
5795 int gap_dedicated_bonding(bd_addr_t device, int mitm_protection_required){
5796 
5797     // create connection state machine
5798     hci_connection_t * connection = create_connection_for_bd_addr_and_type(device, BD_ADDR_TYPE_ACL);
5799 
5800     if (!connection){
5801         return BTSTACK_MEMORY_ALLOC_FAILED;
5802     }
5803 
5804     // delete linkn key
5805     gap_drop_link_key_for_bd_addr(device);
5806 
5807     // configure LEVEL_2/3, dedicated bonding
5808     connection->state = SEND_CREATE_CONNECTION;
5809     connection->requested_security_level = mitm_protection_required ? LEVEL_3 : LEVEL_2;
5810     log_info("gap_dedicated_bonding, mitm %d -> level %u", mitm_protection_required, connection->requested_security_level);
5811     connection->bonding_flags = BONDING_DEDICATED;
5812 
5813     // wait for GAP Security Result and send GAP Dedicated Bonding complete
5814 
5815     // handle: connnection failure (connection complete != ok)
5816     // handle: authentication failure
5817     // handle: disconnect on done
5818 
5819     hci_run();
5820 
5821     return 0;
5822 }
5823 
5824 void gap_set_local_name(const char * local_name){
5825     hci_stack->local_name = local_name;
5826     hci_stack->gap_tasks |= GAP_TASK_SET_LOCAL_NAME;
5827     // also update EIR if not set by user
5828     if (hci_stack->eir_data == NULL){
5829         hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
5830     }
5831     hci_run();
5832 }
5833 #endif
5834 
5835 
5836 #ifdef ENABLE_BLE
5837 
5838 #ifdef ENABLE_LE_CENTRAL
5839 void gap_start_scan(void){
5840     hci_stack->le_scanning_enabled = true;
5841     hci_run();
5842 }
5843 
5844 void gap_stop_scan(void){
5845     hci_stack->le_scanning_enabled = false;
5846     hci_run();
5847 }
5848 
5849 void gap_set_scan_params(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window, uint8_t scanning_filter_policy){
5850     hci_stack->le_scan_type          = scan_type;
5851     hci_stack->le_scan_filter_policy = scanning_filter_policy;
5852     hci_stack->le_scan_interval      = scan_interval;
5853     hci_stack->le_scan_window        = scan_window;
5854     hci_stack->le_scanning_param_update = true;
5855     hci_run();
5856 }
5857 
5858 void gap_set_scan_parameters(uint8_t scan_type, uint16_t scan_interval, uint16_t scan_window){
5859     gap_set_scan_params(scan_type, scan_interval, scan_window, 0);
5860 }
5861 
5862 uint8_t gap_connect(const bd_addr_t addr, bd_addr_type_t addr_type){
5863     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, addr_type);
5864     if (!conn){
5865         // disallow if le connection is already outgoing
5866         if (hci_is_le_connection_type(addr_type) && hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
5867             log_error("le connection already active");
5868             return ERROR_CODE_COMMAND_DISALLOWED;
5869         }
5870 
5871         log_info("gap_connect: no connection exists yet, creating context");
5872         conn = create_connection_for_bd_addr_and_type(addr, addr_type);
5873         if (!conn){
5874             // notify client that alloc failed
5875             hci_emit_le_connection_complete(addr_type, addr, 0, BTSTACK_MEMORY_ALLOC_FAILED);
5876             log_info("gap_connect: failed to alloc hci_connection_t");
5877             return GATT_CLIENT_NOT_CONNECTED; // don't sent packet to controller
5878         }
5879 
5880         // set le connecting state
5881         if (hci_is_le_connection_type(addr_type)){
5882             hci_stack->le_connecting_request = LE_CONNECTING_DIRECT;
5883         }
5884 
5885         conn->state = SEND_CREATE_CONNECTION;
5886         log_info("gap_connect: send create connection next");
5887         hci_run();
5888         return ERROR_CODE_SUCCESS;
5889     }
5890 
5891     if (!hci_is_le_connection(conn) ||
5892         (conn->state == SEND_CREATE_CONNECTION) ||
5893         (conn->state == SENT_CREATE_CONNECTION)) {
5894         hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_COMMAND_DISALLOWED);
5895         log_error("gap_connect: classic connection or connect is already being created");
5896         return GATT_CLIENT_IN_WRONG_STATE;
5897     }
5898 
5899     // check if connection was just disconnected
5900     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
5901         log_info("gap_connect: send create connection (again)");
5902         conn->state = SEND_CREATE_CONNECTION;
5903         hci_run();
5904         return ERROR_CODE_SUCCESS;
5905     }
5906 
5907     log_info("gap_connect: context exists with state %u", conn->state);
5908     hci_emit_le_connection_complete(conn->address_type, conn->address, conn->con_handle, ERROR_CODE_SUCCESS);
5909     hci_run();
5910     return ERROR_CODE_SUCCESS;
5911 }
5912 
5913 // @assumption: only a single outgoing LE Connection exists
5914 static hci_connection_t * gap_get_outgoing_connection(void){
5915     btstack_linked_item_t *it;
5916     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
5917         hci_connection_t * conn = (hci_connection_t *) it;
5918         if (!hci_is_le_connection(conn)) continue;
5919         switch (conn->state){
5920             case SEND_CREATE_CONNECTION:
5921             case SENT_CREATE_CONNECTION:
5922             case SENT_CANCEL_CONNECTION:
5923                 return conn;
5924             default:
5925                 break;
5926         };
5927     }
5928     return NULL;
5929 }
5930 
5931 uint8_t gap_connect_cancel(void){
5932     hci_connection_t * conn = gap_get_outgoing_connection();
5933     if (!conn) return 0;
5934     switch (conn->state){
5935         case SEND_CREATE_CONNECTION:
5936             // skip sending create connection and emit event instead
5937             hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
5938             hci_emit_le_connection_complete(conn->address_type, conn->address, 0, ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER);
5939             btstack_linked_list_remove(&hci_stack->connections, (btstack_linked_item_t *) conn);
5940             btstack_memory_hci_connection_free( conn );
5941             break;
5942         case SENT_CREATE_CONNECTION:
5943             // request to send cancel connection
5944             conn->state = SEND_CANCEL_CONNECTION;
5945             hci_run();
5946             break;
5947         default:
5948             break;
5949     }
5950     return 0;
5951 }
5952 #endif
5953 
5954 #ifdef ENABLE_LE_CENTRAL
5955 /**
5956  * @brief Set connection parameters for outgoing connections
5957  * @param conn_scan_interval (unit: 0.625 msec), default: 60 ms
5958  * @param conn_scan_window (unit: 0.625 msec), default: 30 ms
5959  * @param conn_interval_min (unit: 1.25ms), default: 10 ms
5960  * @param conn_interval_max (unit: 1.25ms), default: 30 ms
5961  * @param conn_latency, default: 4
5962  * @param supervision_timeout (unit: 10ms), default: 720 ms
5963  * @param min_ce_length (unit: 0.625ms), default: 10 ms
5964  * @param max_ce_length (unit: 0.625ms), default: 30 ms
5965  */
5966 
5967 void gap_set_connection_parameters(uint16_t conn_scan_interval, uint16_t conn_scan_window,
5968     uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency,
5969     uint16_t supervision_timeout, uint16_t min_ce_length, uint16_t max_ce_length){
5970     hci_stack->le_connection_scan_interval = conn_scan_interval;
5971     hci_stack->le_connection_scan_window = conn_scan_window;
5972     hci_stack->le_connection_interval_min = conn_interval_min;
5973     hci_stack->le_connection_interval_max = conn_interval_max;
5974     hci_stack->le_connection_latency = conn_latency;
5975     hci_stack->le_supervision_timeout = supervision_timeout;
5976     hci_stack->le_minimum_ce_length = min_ce_length;
5977     hci_stack->le_maximum_ce_length = max_ce_length;
5978 }
5979 #endif
5980 
5981 /**
5982  * @brief Updates the connection parameters for a given LE connection
5983  * @param handle
5984  * @param conn_interval_min (unit: 1.25ms)
5985  * @param conn_interval_max (unit: 1.25ms)
5986  * @param conn_latency
5987  * @param supervision_timeout (unit: 10ms)
5988  * @returns 0 if ok
5989  */
5990 int gap_update_connection_parameters(hci_con_handle_t con_handle, uint16_t conn_interval_min,
5991     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
5992     hci_connection_t * connection = hci_connection_for_handle(con_handle);
5993     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
5994     connection->le_conn_interval_min = conn_interval_min;
5995     connection->le_conn_interval_max = conn_interval_max;
5996     connection->le_conn_latency = conn_latency;
5997     connection->le_supervision_timeout = supervision_timeout;
5998     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS;
5999     hci_run();
6000     return 0;
6001 }
6002 
6003 /**
6004  * @brief Request an update of the connection parameter for a given LE connection
6005  * @param handle
6006  * @param conn_interval_min (unit: 1.25ms)
6007  * @param conn_interval_max (unit: 1.25ms)
6008  * @param conn_latency
6009  * @param supervision_timeout (unit: 10ms)
6010  * @returns 0 if ok
6011  */
6012 int gap_request_connection_parameter_update(hci_con_handle_t con_handle, uint16_t conn_interval_min,
6013     uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout){
6014     hci_connection_t * connection = hci_connection_for_handle(con_handle);
6015     if (!connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6016     connection->le_conn_interval_min = conn_interval_min;
6017     connection->le_conn_interval_max = conn_interval_max;
6018     connection->le_conn_latency = conn_latency;
6019     connection->le_supervision_timeout = supervision_timeout;
6020     connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_REQUEST;
6021     uint8_t l2cap_trigger_run_event[2] = { L2CAP_EVENT_TRIGGER_RUN, 0};
6022     hci_emit_event(l2cap_trigger_run_event, sizeof(l2cap_trigger_run_event), 0);
6023     return 0;
6024 }
6025 
6026 #ifdef ENABLE_LE_PERIPHERAL
6027 
6028 /**
6029  * @brief Set Advertisement Data
6030  * @param advertising_data_length
6031  * @param advertising_data (max 31 octets)
6032  * @note data is not copied, pointer has to stay valid
6033  */
6034 void gap_advertisements_set_data(uint8_t advertising_data_length, uint8_t * advertising_data){
6035     hci_stack->le_advertisements_data_len = advertising_data_length;
6036     hci_stack->le_advertisements_data = advertising_data;
6037     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_ADV_DATA;
6038     hci_run();
6039 }
6040 
6041 /**
6042  * @brief Set Scan Response Data
6043  * @param advertising_data_length
6044  * @param advertising_data (max 31 octets)
6045  * @note data is not copied, pointer has to stay valid
6046  */
6047 void gap_scan_response_set_data(uint8_t scan_response_data_length, uint8_t * scan_response_data){
6048     hci_stack->le_scan_response_data_len = scan_response_data_length;
6049     hci_stack->le_scan_response_data = scan_response_data;
6050     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_SCAN_DATA;
6051     hci_run();
6052 }
6053 
6054 /**
6055  * @brief Set Advertisement Parameters
6056  * @param adv_int_min
6057  * @param adv_int_max
6058  * @param adv_type
6059  * @param direct_address_type
6060  * @param direct_address
6061  * @param channel_map
6062  * @param filter_policy
6063  *
6064  * @note internal use. use gap_advertisements_set_params from gap_le.h instead.
6065  */
6066  void hci_le_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type,
6067     uint8_t direct_address_typ, bd_addr_t direct_address,
6068     uint8_t channel_map, uint8_t filter_policy) {
6069 
6070     hci_stack->le_advertisements_interval_min = adv_int_min;
6071     hci_stack->le_advertisements_interval_max = adv_int_max;
6072     hci_stack->le_advertisements_type = adv_type;
6073     hci_stack->le_advertisements_direct_address_type = direct_address_typ;
6074     hci_stack->le_advertisements_channel_map = channel_map;
6075     hci_stack->le_advertisements_filter_policy = filter_policy;
6076     (void)memcpy(hci_stack->le_advertisements_direct_address, direct_address,
6077                  6);
6078 
6079     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS | LE_ADVERTISEMENT_TASKS_PARAMS_SET;
6080     hci_run();
6081  }
6082 
6083 /**
6084  * @brief Enable/Disable Advertisements
6085  * @param enabled
6086  */
6087 void gap_advertisements_enable(int enabled){
6088     hci_stack->le_advertisements_enabled = enabled != 0;
6089     hci_update_advertisements_enabled_for_current_roles();
6090     hci_run();
6091 }
6092 
6093 #endif
6094 
6095 void hci_le_set_own_address_type(uint8_t own_address_type){
6096     log_info("hci_le_set_own_address_type: old %u, new %u", hci_stack->le_own_addr_type, own_address_type);
6097     if (own_address_type == hci_stack->le_own_addr_type) return;
6098     hci_stack->le_own_addr_type = own_address_type;
6099 
6100 #ifdef ENABLE_LE_PERIPHERAL
6101     // update advertisement parameters, too
6102     hci_stack->le_advertisements_todo |= LE_ADVERTISEMENT_TASKS_SET_PARAMS;
6103     hci_run();
6104 #endif
6105 #ifdef ENABLE_LE_CENTRAL
6106     // note: we don't update scan parameters or modify ongoing connection attempts
6107 #endif
6108 }
6109 
6110 #endif
6111 
6112 uint8_t gap_disconnect(hci_con_handle_t handle){
6113     hci_connection_t * conn = hci_connection_for_handle(handle);
6114     if (!conn){
6115         hci_emit_disconnection_complete(handle, 0);
6116         return 0;
6117     }
6118     // ignore if already disconnected
6119     if (conn->state == RECEIVED_DISCONNECTION_COMPLETE){
6120         return 0;
6121     }
6122     conn->state = SEND_DISCONNECT;
6123     hci_run();
6124     return 0;
6125 }
6126 
6127 int gap_read_rssi(hci_con_handle_t con_handle){
6128     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6129     if (hci_connection == NULL) return 0;
6130     connectionSetAuthenticationFlags(hci_connection, AUTH_FLAG_READ_RSSI);
6131     hci_run();
6132     return 1;
6133 }
6134 
6135 /**
6136  * @brief Get connection type
6137  * @param con_handle
6138  * @result connection_type
6139  */
6140 gap_connection_type_t gap_get_connection_type(hci_con_handle_t connection_handle){
6141     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6142     if (!conn) return GAP_CONNECTION_INVALID;
6143     switch (conn->address_type){
6144         case BD_ADDR_TYPE_LE_PUBLIC:
6145         case BD_ADDR_TYPE_LE_RANDOM:
6146             return GAP_CONNECTION_LE;
6147         case BD_ADDR_TYPE_SCO:
6148             return GAP_CONNECTION_SCO;
6149         case BD_ADDR_TYPE_ACL:
6150             return GAP_CONNECTION_ACL;
6151         default:
6152             return GAP_CONNECTION_INVALID;
6153     }
6154 }
6155 
6156 hci_role_t gap_get_role(hci_con_handle_t connection_handle){
6157     hci_connection_t * conn = hci_connection_for_handle(connection_handle);
6158     if (!conn) return HCI_ROLE_INVALID;
6159     return (hci_role_t) conn->role;
6160 }
6161 
6162 
6163 #ifdef ENABLE_CLASSIC
6164 uint8_t gap_request_role(const bd_addr_t addr, hci_role_t role){
6165     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6166     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6167     conn->request_role = role;
6168     hci_run();
6169     return ERROR_CODE_SUCCESS;
6170 }
6171 #endif
6172 
6173 #ifdef ENABLE_BLE
6174 
6175 uint8_t gap_le_set_phy(hci_con_handle_t con_handle, uint8_t all_phys, uint8_t tx_phys, uint8_t rx_phys, uint8_t phy_options){
6176     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6177     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6178 
6179     conn->le_phy_update_all_phys    = all_phys;
6180     conn->le_phy_update_tx_phys     = tx_phys;
6181     conn->le_phy_update_rx_phys     = rx_phys;
6182     conn->le_phy_update_phy_options = phy_options;
6183 
6184     hci_run();
6185 
6186     return 0;
6187 }
6188 
6189 static uint8_t hci_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6190     // check if already in list
6191     btstack_linked_list_iterator_t it;
6192     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6193     while (btstack_linked_list_iterator_has_next(&it)) {
6194         whitelist_entry_t *entry = (whitelist_entry_t *) btstack_linked_list_iterator_next(&it);
6195         if (entry->address_type != address_type) {
6196             continue;
6197         }
6198         if (memcmp(entry->address, address, 6) != 0) {
6199             continue;
6200         }
6201 		// disallow if already scheduled to add
6202 		if ((entry->state & LE_WHITELIST_ADD_TO_CONTROLLER) != 0){
6203 			return ERROR_CODE_COMMAND_DISALLOWED;
6204 		}
6205 		// still on controller, but scheduled to remove -> re-add
6206 		entry->state |= LE_WHITELIST_ADD_TO_CONTROLLER;
6207 		return ERROR_CODE_SUCCESS;
6208     }
6209     // alloc and add to list
6210     whitelist_entry_t * entry = btstack_memory_whitelist_entry_get();
6211     if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED;
6212     entry->address_type = address_type;
6213     (void)memcpy(entry->address, address, 6);
6214     entry->state = LE_WHITELIST_ADD_TO_CONTROLLER;
6215     btstack_linked_list_add(&hci_stack->le_whitelist, (btstack_linked_item_t*) entry);
6216     return ERROR_CODE_SUCCESS;
6217 }
6218 
6219 static uint8_t hci_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6220     btstack_linked_list_iterator_t it;
6221     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6222     while (btstack_linked_list_iterator_has_next(&it)){
6223         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6224         if (entry->address_type != address_type) {
6225             continue;
6226         }
6227         if (memcmp(entry->address, address, 6) != 0) {
6228             continue;
6229         }
6230         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6231             // remove from controller if already present
6232             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6233         }  else {
6234             // directly remove entry from whitelist
6235             btstack_linked_list_iterator_remove(&it);
6236             btstack_memory_whitelist_entry_free(entry);
6237         }
6238         return ERROR_CODE_SUCCESS;
6239     }
6240     return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6241 }
6242 
6243 static void hci_whitelist_clear(void){
6244     btstack_linked_list_iterator_t it;
6245     btstack_linked_list_iterator_init(&it, &hci_stack->le_whitelist);
6246     while (btstack_linked_list_iterator_has_next(&it)){
6247         whitelist_entry_t * entry = (whitelist_entry_t*) btstack_linked_list_iterator_next(&it);
6248         if (entry->state & LE_WHITELIST_ON_CONTROLLER){
6249             // remove from controller if already present
6250             entry->state |= LE_WHITELIST_REMOVE_FROM_CONTROLLER;
6251             continue;
6252         }
6253         // directly remove entry from whitelist
6254         btstack_linked_list_iterator_remove(&it);
6255         btstack_memory_whitelist_entry_free(entry);
6256     }
6257 }
6258 
6259 /**
6260  * @brief Clear Whitelist
6261  * @returns 0 if ok
6262  */
6263 uint8_t gap_whitelist_clear(void){
6264     hci_whitelist_clear();
6265     hci_run();
6266     return ERROR_CODE_SUCCESS;
6267 }
6268 
6269 /**
6270  * @brief Add Device to Whitelist
6271  * @param address_typ
6272  * @param address
6273  * @returns 0 if ok
6274  */
6275 uint8_t gap_whitelist_add(bd_addr_type_t address_type, const bd_addr_t address){
6276     uint8_t status = hci_whitelist_add(address_type, address);
6277     if (status){
6278         return status;
6279     }
6280     hci_run();
6281     return ERROR_CODE_SUCCESS;
6282 }
6283 
6284 /**
6285  * @brief Remove Device from Whitelist
6286  * @param address_typ
6287  * @param address
6288  * @returns 0 if ok
6289  */
6290 uint8_t gap_whitelist_remove(bd_addr_type_t address_type, const bd_addr_t address){
6291     uint8_t status = hci_whitelist_remove(address_type, address);
6292     if (status){
6293         return status;
6294     }
6295     hci_run();
6296     return ERROR_CODE_SUCCESS;
6297 }
6298 
6299 #ifdef ENABLE_LE_CENTRAL
6300 /**
6301  *  @brief Connect with Whitelist
6302  *  @note Explicit whitelist management and this connect with whitelist replace deprecated gap_auto_connection_* functions
6303  *  @returns - if ok
6304  */
6305 uint8_t gap_connect_with_whitelist(void){
6306     if (hci_stack->le_connecting_request != LE_CONNECTING_IDLE){
6307         return ERROR_CODE_COMMAND_DISALLOWED;
6308     }
6309     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6310     hci_run();
6311     return ERROR_CODE_SUCCESS;
6312 }
6313 
6314 /**
6315  * @brief Auto Connection Establishment - Start Connecting to device
6316  * @param address_typ
6317  * @param address
6318  * @returns 0 if ok
6319  */
6320 uint8_t gap_auto_connection_start(bd_addr_type_t address_type, const bd_addr_t address){
6321     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6322         return ERROR_CODE_COMMAND_DISALLOWED;
6323     }
6324 
6325     uint8_t status = hci_whitelist_add(address_type, address);
6326     if (status == BTSTACK_MEMORY_ALLOC_FAILED) {
6327         return status;
6328     }
6329 
6330     hci_stack->le_connecting_request = LE_CONNECTING_WHITELIST;
6331 
6332     hci_run();
6333     return ERROR_CODE_SUCCESS;
6334 }
6335 
6336 /**
6337  * @brief Auto Connection Establishment - Stop Connecting to device
6338  * @param address_typ
6339  * @param address
6340  * @returns 0 if ok
6341  */
6342 uint8_t gap_auto_connection_stop(bd_addr_type_t address_type, const bd_addr_t address){
6343     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT){
6344         return ERROR_CODE_COMMAND_DISALLOWED;
6345     }
6346 
6347     hci_whitelist_remove(address_type, address);
6348     if (btstack_linked_list_empty(&hci_stack->le_whitelist)){
6349         hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6350     }
6351     hci_run();
6352     return 0;
6353 }
6354 
6355 /**
6356  * @brief Auto Connection Establishment - Stop everything
6357  * @note  Convenience function to stop all active auto connection attempts
6358  */
6359 uint8_t gap_auto_connection_stop_all(void){
6360     if (hci_stack->le_connecting_request == LE_CONNECTING_DIRECT) {
6361         return ERROR_CODE_COMMAND_DISALLOWED;
6362     }
6363     hci_whitelist_clear();
6364     hci_stack->le_connecting_request = LE_CONNECTING_IDLE;
6365     hci_run();
6366     return ERROR_CODE_SUCCESS;
6367 }
6368 
6369 uint16_t gap_le_connection_interval(hci_con_handle_t con_handle){
6370     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6371     if (!conn) return 0;
6372     return conn->le_connection_interval;
6373 }
6374 #endif
6375 #endif
6376 
6377 #ifdef ENABLE_CLASSIC
6378 /**
6379  * @brief Set Extended Inquiry Response data
6380  * @param eir_data size HCI_EXTENDED_INQUIRY_RESPONSE_DATA_LEN (240) bytes, is not copied make sure memory is accessible during stack startup
6381  * @note has to be done before stack starts up
6382  */
6383 void gap_set_extended_inquiry_response(const uint8_t * data){
6384     hci_stack->eir_data = data;
6385     hci_stack->gap_tasks |= GAP_TASK_SET_EIR_DATA;
6386     hci_run();
6387 }
6388 
6389 /**
6390  * @brief Start GAP Classic Inquiry
6391  * @param duration in 1.28s units
6392  * @return 0 if ok
6393  * @events: GAP_EVENT_INQUIRY_RESULT, GAP_EVENT_INQUIRY_COMPLETE
6394  */
6395 int gap_inquiry_start(uint8_t duration_in_1280ms_units){
6396     if (hci_stack->state != HCI_STATE_WORKING) return ERROR_CODE_COMMAND_DISALLOWED;
6397     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6398     if ((duration_in_1280ms_units < GAP_INQUIRY_DURATION_MIN) || (duration_in_1280ms_units > GAP_INQUIRY_DURATION_MAX)){
6399         return ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS;
6400     }
6401     hci_stack->inquiry_state = duration_in_1280ms_units;
6402     hci_run();
6403     return 0;
6404 }
6405 
6406 /**
6407  * @brief Stop GAP Classic Inquiry
6408  * @returns 0 if ok
6409  */
6410 int gap_inquiry_stop(void){
6411     if ((hci_stack->inquiry_state >= GAP_INQUIRY_DURATION_MIN) && (hci_stack->inquiry_state <= GAP_INQUIRY_DURATION_MAX)) {
6412         // emit inquiry complete event, before it even started
6413         uint8_t event[] = { GAP_EVENT_INQUIRY_COMPLETE, 1, 0};
6414         hci_emit_event(event, sizeof(event), 1);
6415         return 0;
6416     }
6417     if (hci_stack->inquiry_state != GAP_INQUIRY_STATE_ACTIVE) return ERROR_CODE_COMMAND_DISALLOWED;
6418     hci_stack->inquiry_state = GAP_INQUIRY_STATE_W2_CANCEL;
6419     hci_run();
6420     return 0;
6421 }
6422 
6423 void gap_inquiry_set_lap(uint32_t lap){
6424     hci_stack->inquiry_lap = lap;
6425 }
6426 
6427 
6428 /**
6429  * @brief Remote Name Request
6430  * @param addr
6431  * @param page_scan_repetition_mode
6432  * @param clock_offset only used when bit 15 is set
6433  * @events: HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE
6434  */
6435 int gap_remote_name_request(const bd_addr_t addr, uint8_t page_scan_repetition_mode, uint16_t clock_offset){
6436     if (hci_stack->remote_name_state != GAP_REMOTE_NAME_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6437     (void)memcpy(hci_stack->remote_name_addr, addr, 6);
6438     hci_stack->remote_name_page_scan_repetition_mode = page_scan_repetition_mode;
6439     hci_stack->remote_name_clock_offset = clock_offset;
6440     hci_stack->remote_name_state = GAP_REMOTE_NAME_STATE_W2_SEND;
6441     hci_run();
6442     return 0;
6443 }
6444 
6445 static int gap_pairing_set_state_and_run(const bd_addr_t addr, uint8_t state){
6446     hci_stack->gap_pairing_state = state;
6447     (void)memcpy(hci_stack->gap_pairing_addr, addr, 6);
6448     hci_run();
6449     return 0;
6450 }
6451 
6452 /**
6453  * @brief Legacy Pairing Pin Code Response for binary data / non-strings
6454  * @param addr
6455  * @param pin_data
6456  * @param pin_len
6457  * @return 0 if ok
6458  */
6459 int gap_pin_code_response_binary(const bd_addr_t addr, const uint8_t * pin_data, uint8_t pin_len){
6460     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6461     hci_stack->gap_pairing_input.gap_pairing_pin = pin_data;
6462     hci_stack->gap_pairing_pin_len = pin_len;
6463     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN);
6464 }
6465 
6466 /**
6467  * @brief Legacy Pairing Pin Code Response
6468  * @param addr
6469  * @param pin
6470  * @return 0 if ok
6471  */
6472 int gap_pin_code_response(const bd_addr_t addr, const char * pin){
6473     return gap_pin_code_response_binary(addr, (const uint8_t*) pin, strlen(pin));
6474 }
6475 
6476 /**
6477  * @brief Abort Legacy Pairing
6478  * @param addr
6479  * @param pin
6480  * @return 0 if ok
6481  */
6482 int gap_pin_code_negative(bd_addr_t addr){
6483     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6484     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PIN_NEGATIVE);
6485 }
6486 
6487 /**
6488  * @brief SSP Passkey Response
6489  * @param addr
6490  * @param passkey
6491  * @return 0 if ok
6492  */
6493 int gap_ssp_passkey_response(const bd_addr_t addr, uint32_t passkey){
6494     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6495     hci_stack->gap_pairing_input.gap_pairing_passkey = passkey;
6496     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY);
6497 }
6498 
6499 /**
6500  * @brief Abort SSP Passkey Entry/Pairing
6501  * @param addr
6502  * @param pin
6503  * @return 0 if ok
6504  */
6505 int gap_ssp_passkey_negative(const bd_addr_t addr){
6506     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6507     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_PASSKEY_NEGATIVE);
6508 }
6509 
6510 /**
6511  * @brief Accept SSP Numeric Comparison
6512  * @param addr
6513  * @param passkey
6514  * @return 0 if ok
6515  */
6516 int gap_ssp_confirmation_response(const bd_addr_t addr){
6517     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6518     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION);
6519 }
6520 
6521 /**
6522  * @brief Abort SSP Numeric Comparison/Pairing
6523  * @param addr
6524  * @param pin
6525  * @return 0 if ok
6526  */
6527 int gap_ssp_confirmation_negative(const bd_addr_t addr){
6528     if (hci_stack->gap_pairing_state != GAP_PAIRING_STATE_IDLE) return ERROR_CODE_COMMAND_DISALLOWED;
6529     return gap_pairing_set_state_and_run(addr, GAP_PAIRING_STATE_SEND_CONFIRMATION_NEGATIVE);
6530 }
6531 
6532 #if defined(ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY) || defined(ENABLE_EXPLICIT_LINK_KEY_REPLY)
6533 static uint8_t gap_set_auth_flag_and_run(const bd_addr_t addr, hci_authentication_flags_t flag){
6534     hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6535     if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6536     connectionSetAuthenticationFlags(conn, flag);
6537     hci_run();
6538     return ERROR_CODE_SUCCESS;
6539 }
6540 #endif
6541 
6542 #ifdef ENABLE_EXPLICIT_IO_CAPABILITIES_REPLY
6543 uint8_t gap_ssp_io_capabilities_response(const bd_addr_t addr){
6544     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_REPLY);
6545 }
6546 
6547 uint8_t gap_ssp_io_capabilities_negative(const bd_addr_t addr){
6548     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_SEND_IO_CAPABILITIES_NEGATIVE_REPLY);
6549 }
6550 #endif
6551 
6552 #ifdef ENABLE_CLASSIC_PAIRING_OOB
6553 /**
6554  * @brief Report Remote OOB Data
6555  * @param bd_addr
6556  * @param c_192 Simple Pairing Hash C derived from P-192 public key
6557  * @param r_192 Simple Pairing Randomizer derived from P-192 public key
6558  * @param c_256 Simple Pairing Hash C derived from P-256 public key
6559  * @param r_256 Simple Pairing Randomizer derived from P-256 public key
6560  */
6561 uint8_t gap_ssp_remote_oob_data(const bd_addr_t addr, const uint8_t * c_192, const uint8_t * r_192, const uint8_t * c_256, const uint8_t * r_256){
6562     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6563     if (connection == NULL) {
6564         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6565     }
6566     connection->classic_oob_c_192 = c_192;
6567     connection->classic_oob_r_192 = r_192;
6568 
6569     // ignore P-256 if not supported by us
6570     if (hci_stack->secure_connections_active){
6571         connection->classic_oob_c_256 = c_256;
6572         connection->classic_oob_r_256 = r_256;
6573     }
6574 
6575     return ERROR_CODE_SUCCESS;
6576 }
6577 /**
6578  * @brief Generate new OOB data
6579  * @note OOB data will be provided in GAP_EVENT_LOCAL_OOB_DATA and be used in future pairing procedures
6580  */
6581 void gap_ssp_generate_oob_data(void){
6582     hci_stack->classic_read_local_oob_data = true;
6583     hci_run();
6584 }
6585 
6586 #endif
6587 
6588 #ifdef ENABLE_EXPLICIT_LINK_KEY_REPLY
6589 uint8_t gap_send_link_key_response(const bd_addr_t addr, link_key_t link_key, link_key_type_t type){
6590     hci_connection_t * connection = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6591     if (connection == NULL) {
6592         return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
6593     }
6594 
6595     memcpy(connection->link_key, link_key, sizeof(link_key_t));
6596     connection->link_key_type = type;
6597 
6598     return gap_set_auth_flag_and_run(addr, AUTH_FLAG_HANDLE_LINK_KEY_REQUEST);
6599 }
6600 
6601 #endif // ENABLE_EXPLICIT_LINK_KEY_REPLY
6602 /**
6603  * @brief Set inquiry mode: standard, with RSSI, with RSSI + Extended Inquiry Results. Has to be called before power on.
6604  * @param inquiry_mode see bluetooth_defines.h
6605  */
6606 void hci_set_inquiry_mode(inquiry_mode_t inquiry_mode){
6607     hci_stack->inquiry_mode = inquiry_mode;
6608 }
6609 
6610 /**
6611  * @brief Configure Voice Setting for use with SCO data in HSP/HFP
6612  */
6613 void hci_set_sco_voice_setting(uint16_t voice_setting){
6614     hci_stack->sco_voice_setting = voice_setting;
6615 }
6616 
6617 /**
6618  * @brief Get SCO Voice Setting
6619  * @return current voice setting
6620  */
6621 uint16_t hci_get_sco_voice_setting(void){
6622     return hci_stack->sco_voice_setting;
6623 }
6624 
6625 static int hci_have_usb_transport(void){
6626     if (!hci_stack->hci_transport) return 0;
6627     const char * transport_name = hci_stack->hci_transport->name;
6628     if (!transport_name) return 0;
6629     return (transport_name[0] == 'H') && (transport_name[1] == '2');
6630 }
6631 
6632 /** @brief Get SCO packet length for current SCO Voice setting
6633  *  @note  Using SCO packets of the exact length is required for USB transfer
6634  *  @return Length of SCO packets in bytes (not audio frames)
6635  */
6636 uint16_t hci_get_sco_packet_length(void){
6637     uint16_t sco_packet_length = 0;
6638 
6639 #ifdef ENABLE_SCO_OVER_HCI
6640     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6641     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6642 
6643     if (hci_have_usb_transport()){
6644         // see Core Spec for H2 USB Transfer.
6645         // 3 byte SCO header + 24 bytes per connection
6646         int num_sco_connections = btstack_max(1, hci_number_sco_connections());
6647         sco_packet_length = 3 + 24 * num_sco_connections * multiplier;
6648     } else {
6649         // 3 byte SCO header + SCO packet size over the air (60 bytes)
6650         sco_packet_length = 3 + 60 * multiplier;
6651         // assert that it still fits inside an SCO buffer
6652         if (sco_packet_length > hci_stack->sco_data_packet_length){
6653             sco_packet_length = 3 + 60;
6654         }
6655     }
6656 #endif
6657 
6658 #ifdef HAVE_SCO_TRANSPORT
6659     // Transparent = mSBC => 1, CVSD with 16-bit samples requires twice as much bytes
6660     int multiplier = ((hci_stack->sco_voice_setting_active & 0x03) == 0x03) ? 1 : 2;
6661     sco_packet_length = 3 + 60 * multiplier;
6662 #endif
6663     return sco_packet_length;
6664 }
6665 
6666 /**
6667 * @brief Sets the master/slave policy
6668 * @param policy (0: attempt to become master, 1: let connecting device decide)
6669 */
6670 void hci_set_master_slave_policy(uint8_t policy){
6671     hci_stack->master_slave_policy = policy;
6672 }
6673 
6674 #endif
6675 
6676 HCI_STATE hci_get_state(void){
6677     return hci_stack->state;
6678 }
6679 
6680 #ifdef ENABLE_CLASSIC
6681 void gap_register_classic_connection_filter(int (*accept_callback)(bd_addr_t addr, hci_link_type_t link_type)){
6682     hci_stack->gap_classic_accept_callback = accept_callback;
6683 }
6684 #endif
6685 
6686 /**
6687  * @brief Set callback for Bluetooth Hardware Error
6688  */
6689 void hci_set_hardware_error_callback(void (*fn)(uint8_t error)){
6690     hci_stack->hardware_error_callback = fn;
6691 }
6692 
6693 void hci_disconnect_all(void){
6694     btstack_linked_list_iterator_t it;
6695     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6696     while (btstack_linked_list_iterator_has_next(&it)){
6697         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6698         if (con->state == SENT_DISCONNECT) continue;
6699         con->state = SEND_DISCONNECT;
6700     }
6701     hci_run();
6702 }
6703 
6704 uint16_t hci_get_manufacturer(void){
6705     return hci_stack->manufacturer;
6706 }
6707 
6708 #ifdef ENABLE_BLE
6709 static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){
6710     hci_connection_t * hci_con = hci_connection_for_handle(con_handle);
6711     if (!hci_con) return NULL;
6712     return &hci_con->sm_connection;
6713 }
6714 
6715 // extracted from sm.c to allow enabling of l2cap le data channels without adding sm.c to the build
6716 // without sm.c default values from create_connection_for_bd_addr_and_type() resulg in non-encrypted, not-authenticated
6717 #endif
6718 
6719 int gap_encryption_key_size(hci_con_handle_t con_handle){
6720     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6721     if (hci_connection == NULL) return 0;
6722     if (hci_is_le_connection(hci_connection)){
6723 #ifdef ENABLE_BLE
6724         sm_connection_t * sm_conn = &hci_connection->sm_connection;
6725         if (sm_conn->sm_connection_encrypted) {
6726             return sm_conn->sm_actual_encryption_key_size;
6727         }
6728 #endif
6729     } else {
6730 #ifdef ENABLE_CLASSIC
6731         if ((hci_connection->authentication_flags & AUTH_FLAG_CONNECTION_ENCRYPTED)){
6732             return hci_connection->encryption_key_size;
6733         }
6734 #endif
6735     }
6736     return 0;
6737 }
6738 
6739 int gap_authenticated(hci_con_handle_t con_handle){
6740     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6741     if (hci_connection == NULL) return 0;
6742 
6743     switch (hci_connection->address_type){
6744 #ifdef ENABLE_BLE
6745         case BD_ADDR_TYPE_LE_PUBLIC:
6746         case BD_ADDR_TYPE_LE_RANDOM:
6747             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6748             return hci_connection->sm_connection.sm_connection_authenticated;
6749 #endif
6750 #ifdef ENABLE_CLASSIC
6751         case BD_ADDR_TYPE_SCO:
6752         case BD_ADDR_TYPE_ACL:
6753             return gap_authenticated_for_link_key_type(hci_connection->link_key_type);
6754 #endif
6755         default:
6756             return 0;
6757     }
6758 }
6759 
6760 int gap_secure_connection(hci_con_handle_t con_handle){
6761     hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6762     if (hci_connection == NULL) return 0;
6763 
6764     switch (hci_connection->address_type){
6765 #ifdef ENABLE_BLE
6766         case BD_ADDR_TYPE_LE_PUBLIC:
6767         case BD_ADDR_TYPE_LE_RANDOM:
6768             if (hci_connection->sm_connection.sm_connection_encrypted == 0) return 0; // unencrypted connection cannot be authenticated
6769             return hci_connection->sm_connection.sm_connection_sc;
6770 #endif
6771 #ifdef ENABLE_CLASSIC
6772         case BD_ADDR_TYPE_SCO:
6773         case BD_ADDR_TYPE_ACL:
6774             return gap_secure_connection_for_link_key_type(hci_connection->link_key_type);
6775 #endif
6776         default:
6777             return 0;
6778     }
6779 }
6780 
6781 bool gap_bonded(hci_con_handle_t con_handle){
6782 	hci_connection_t * hci_connection = hci_connection_for_handle(con_handle);
6783 	if (hci_connection == NULL) return 0;
6784 
6785 #ifdef ENABLE_CLASSIC
6786 	link_key_t link_key;
6787 	link_key_type_t link_key_type;
6788 #endif
6789 	switch (hci_connection->address_type){
6790 #ifdef ENABLE_BLE
6791 		case BD_ADDR_TYPE_LE_PUBLIC:
6792 		case BD_ADDR_TYPE_LE_RANDOM:
6793 			return hci_connection->sm_connection.sm_le_db_index >= 0;
6794 #endif
6795 #ifdef ENABLE_CLASSIC
6796 		case BD_ADDR_TYPE_SCO:
6797 		case BD_ADDR_TYPE_ACL:
6798 			return hci_stack->link_key_db && hci_stack->link_key_db->get_link_key(hci_connection->address, link_key, &link_key_type);
6799 #endif
6800 		default:
6801 			return false;
6802 	}
6803 }
6804 
6805 #ifdef ENABLE_BLE
6806 authorization_state_t gap_authorization_state(hci_con_handle_t con_handle){
6807     sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
6808     if (!sm_conn) return AUTHORIZATION_UNKNOWN;     // wrong connection
6809     if (!sm_conn->sm_connection_encrypted)               return AUTHORIZATION_UNKNOWN; // unencrypted connection cannot be authorized
6810     if (!sm_conn->sm_connection_authenticated)           return AUTHORIZATION_UNKNOWN; // unauthenticatd connection cannot be authorized
6811     return sm_conn->sm_connection_authorization_state;
6812 }
6813 #endif
6814 
6815 #ifdef ENABLE_CLASSIC
6816 uint8_t gap_sniff_mode_enter(hci_con_handle_t con_handle, uint16_t sniff_min_interval, uint16_t sniff_max_interval, uint16_t sniff_attempt, uint16_t sniff_timeout){
6817     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6818     if (!conn) return GAP_CONNECTION_INVALID;
6819     conn->sniff_min_interval = sniff_min_interval;
6820     conn->sniff_max_interval = sniff_max_interval;
6821     conn->sniff_attempt = sniff_attempt;
6822     conn->sniff_timeout = sniff_timeout;
6823     hci_run();
6824     return 0;
6825 }
6826 
6827 /**
6828  * @brief Exit Sniff mode
6829  * @param con_handle
6830  @ @return 0 if ok
6831  */
6832 uint8_t gap_sniff_mode_exit(hci_con_handle_t con_handle){
6833     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6834     if (!conn) return GAP_CONNECTION_INVALID;
6835     conn->sniff_min_interval = 0xffff;
6836     hci_run();
6837     return 0;
6838 }
6839 
6840 uint8_t gap_sniff_subrating_configure(hci_con_handle_t con_handle, uint16_t max_latency, uint16_t min_remote_timeout, uint16_t min_local_timeout){
6841     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6842     if (!conn) return GAP_CONNECTION_INVALID;
6843     conn->sniff_subrating_max_latency = max_latency;
6844     conn->sniff_subrating_min_remote_timeout = min_remote_timeout;
6845     conn->sniff_subrating_min_local_timeout = min_local_timeout;
6846     hci_run();
6847     return ERROR_CODE_SUCCESS;
6848 }
6849 
6850 uint8_t gap_qos_set(hci_con_handle_t con_handle, hci_service_type_t service_type, uint32_t token_rate, uint32_t peak_bandwidth, uint32_t latency, uint32_t delay_variation){
6851     hci_connection_t * conn = hci_connection_for_handle(con_handle);
6852     if (!conn) return GAP_CONNECTION_INVALID;
6853     conn->qos_service_type = service_type;
6854     conn->qos_token_rate = token_rate;
6855     conn->qos_peak_bandwidth = peak_bandwidth;
6856     conn->qos_latency = latency;
6857     conn->qos_delay_variation = delay_variation;
6858     hci_run();
6859     return ERROR_CODE_SUCCESS;
6860 }
6861 
6862 void gap_set_page_scan_activity(uint16_t page_scan_interval, uint16_t page_scan_window){
6863     hci_stack->new_page_scan_interval = page_scan_interval;
6864     hci_stack->new_page_scan_window = page_scan_window;
6865     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_ACTIVITY;
6866     hci_run();
6867 }
6868 
6869 void gap_set_page_scan_type(page_scan_type_t page_scan_type){
6870     hci_stack->new_page_scan_type = (uint8_t) page_scan_type;
6871     hci_stack->gap_tasks |= GAP_TASK_WRITE_PAGE_SCAN_TYPE;
6872     hci_run();
6873 }
6874 
6875 #endif
6876 
6877 void hci_halting_defer(void){
6878     if (hci_stack->state != HCI_STATE_HALTING) return;
6879     switch (hci_stack->substate){
6880         case HCI_HALTING_DISCONNECT_ALL_NO_TIMER:
6881         case HCI_HALTING_CLOSE:
6882             hci_stack->substate = HCI_HALTING_DISCONNECT_ALL_TIMER;
6883             break;
6884         default:
6885             break;
6886     }
6887 }
6888 
6889 #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION
6890 void hci_load_le_device_db_entry_into_resolving_list(uint16_t le_device_db_index){
6891     if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6892     if (le_device_db_index >= le_device_db_max_count()) return;
6893     uint8_t offset = le_device_db_index >> 3;
6894     uint8_t mask = 1 << (le_device_db_index & 7);
6895     hci_stack->le_resolving_list_add_entries[offset] |= mask;
6896     if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6897     	// note: go back to remove entries, otherwise, a remove + add will skip the add
6898         hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6899     }
6900 }
6901 
6902 void hci_remove_le_device_db_entry_from_resolving_list(uint16_t le_device_db_index){
6903 	if (le_device_db_index >= MAX_NUM_RESOLVING_LIST_ENTRIES) return;
6904 	if (le_device_db_index >= le_device_db_max_count()) return;
6905 	uint8_t offset = le_device_db_index >> 3;
6906 	uint8_t mask = 1 << (le_device_db_index & 7);
6907 	hci_stack->le_resolving_list_remove_entries[offset] |= mask;
6908 	if (hci_stack->le_resolving_list_state == LE_RESOLVING_LIST_DONE){
6909 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_REMOVE_ENTRIES;
6910 	}
6911 }
6912 
6913 uint8_t gap_load_resolving_list_from_le_device_db(void){
6914 	if ((hci_stack->local_supported_commands[1] & (1 << 2)) == 0) {
6915 		return ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE;
6916 	}
6917 	if (hci_stack->le_resolving_list_state != LE_RESOLVING_LIST_SEND_ENABLE_ADDRESS_RESOLUTION){
6918 		// restart le resolving list update
6919 		hci_stack->le_resolving_list_state = LE_RESOLVING_LIST_READ_SIZE;
6920 	}
6921 	return ERROR_CODE_SUCCESS;
6922 }
6923 #endif
6924 
6925 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
6926 void hci_setup_test_connections_fuzz(void){
6927     hci_connection_t * conn;
6928 
6929     // default address: 66:55:44:33:00:01
6930     bd_addr_t addr = { 0x66, 0x55, 0x44, 0x33, 0x00, 0x00};
6931 
6932     // setup Controller info
6933     hci_stack->num_cmd_packets = 255;
6934     hci_stack->acl_packets_total_num = 255;
6935 
6936     // setup incoming Classic ACL connection with con handle 0x0001, 66:55:44:33:22:01
6937     addr[5] = 0x01;
6938     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6939     conn->con_handle = addr[5];
6940     conn->role  = HCI_ROLE_SLAVE;
6941     conn->state = RECEIVED_CONNECTION_REQUEST;
6942     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6943 
6944     // setup incoming Classic SCO connection with con handle 0x0002
6945     addr[5] = 0x02;
6946     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6947     conn->con_handle = addr[5];
6948     conn->role  = HCI_ROLE_SLAVE;
6949     conn->state = RECEIVED_CONNECTION_REQUEST;
6950     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6951 
6952     // setup ready Classic ACL connection with con handle 0x0003
6953     addr[5] = 0x03;
6954     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
6955     conn->con_handle = addr[5];
6956     conn->role  = HCI_ROLE_SLAVE;
6957     conn->state = OPEN;
6958     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6959 
6960     // setup ready Classic SCO connection with con handle 0x0004
6961     addr[5] = 0x04;
6962     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_SCO);
6963     conn->con_handle = addr[5];
6964     conn->role  = HCI_ROLE_SLAVE;
6965     conn->state = OPEN;
6966     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6967 
6968     // setup ready LE ACL connection with con handle 0x005 and public address
6969     addr[5] = 0x05;
6970     conn = create_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_LE_PUBLIC);
6971     conn->con_handle = addr[5];
6972     conn->role  = HCI_ROLE_SLAVE;
6973     conn->state = OPEN;
6974     conn->sm_connection.sm_role = HCI_ROLE_SLAVE;
6975     conn->sm_connection.sm_connection_encrypted = 1;
6976 }
6977 
6978 void hci_free_connections_fuzz(void){
6979     btstack_linked_list_iterator_t it;
6980     btstack_linked_list_iterator_init(&it, &hci_stack->connections);
6981     while (btstack_linked_list_iterator_has_next(&it)){
6982         hci_connection_t * con = (hci_connection_t*) btstack_linked_list_iterator_next(&it);
6983         btstack_linked_list_iterator_remove(&it);
6984         btstack_memory_hci_connection_free(con);
6985     }
6986 }
6987 void hci_simulate_working_fuzz(void){
6988     hci_init_done();
6989     hci_stack->num_cmd_packets = 255;
6990 }
6991 #endif
6992